0000034088-21-000012 | 10-K | XBRL Viewer

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Document And Entity Information - USD ($) $ in Billions	12 Months Ended
Document And Entity Information - USD ($) $ in Billions	Dec. 31, 2020	Jan. 31, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Transition Report	false
Entity File Number	1-2256
Entity Registrant Name	Exxon Mobil Corporation
Entity Incorporation, State or Country Code	NJ
Entity Tax Identification Number	13-5409005
Entity Address Address Line 1	5959 Las Colinas Boulevard
Entity Address City or Town	Irving
Entity Address State or Province	TX
Entity Address Postal Zip Code	75039-2298
City Area Code	972
Local Phone Number	940-6000
Document Information [Line Items]
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 189
Entity Common Stock Shares Outstanding		4,233,483,160
Amendment Flag	false
Documents Incorporated by Reference Text Block	Proxy Statement for the 2021 Annual Meeting of Shareholders (Part III)
Document Fiscal Period Focus	FY
Entity Central Index Key	0000034088
Current Fiscal Year End Date	--12-31
Common Stock, without par value [Member]
Document Information [Line Items]
Security 12(b) Title	Common Stock, without par value
Trading Symbol	XOM
Security Exchange Name	NYSE
0.142% Notes Due in 2024 [Member]
Document Information [Line Items]
Security 12(b) Title	0.142% Notes due 2024
Trading Symbol	XOM24B
Security Exchange Name	NYSE
0.524% Notes Due in 2028 [Member]
Document Information [Line Items]
Security 12(b) Title	0.524% Notes due 2028
Trading Symbol	XOM28
Security Exchange Name	NYSE
0.835% Notes Due in 2032 [Member]
Document Information [Line Items]
Security 12(b) Title	0.835% Notes due 2032
Trading Symbol	XOM32
Security Exchange Name	NYSE
1.408% Notes Due in 2039 [Member]
Document Information [Line Items]
Security 12(b) Title	1.408% Notes due 2039
Trading Symbol	XOM39A
Security Exchange Name	NYSE

Consolidated Statement Of Income - USD ($) $ in Millions	12 Months Ended
Consolidated Statement Of Income - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues and other income
Sales and other operating revenue	$ 178,574	$ 255,583	$ 279,332
Income from equity affiliates	1,732	5,441	7,355
Other income	1,196	3,914	3,525
Total revenues and other income	181,502	264,938	290,212
Costs and other deductions
Crude oil and product purchases	94,007	143,801	156,172
Production and manufacturing expenses	30,431	36,826	36,682
Selling, general and administrative expenses	10,168	11,398	11,480
Depreciation and depletion (includes impairments)	46,009	18,998	18,745
Exploration expenses, including dry holes	1,285	1,269	1,466
Non-service pension and postretirement benefit expense	1,205	1,235	1,285
Interest expense	1,158	830	766
Other taxes and duties	26,122	30,525	32,663
Total costs and other deductions	210,385	244,882	259,259
Income (Loss) before income taxes	(28,883)	20,056	30,953
Income tax expense (benefit)	(5,632)	5,282	9,532
Net income (loss) including noncontrolling interests	(23,251)	14,774	21,421
Net income (loss) attributable to noncontrolling interests	(811)	434	581
Net income (loss) attributable to ExxonMobil	$ (22,440)	$ 14,340	$ 20,840
Earnings (Loss) per common share (dollars)	$ (5.25)	$ 3.36	$ 4.88
Earnings (Loss) per common share - assuming dilution (dollars)	$ (5.25)	$ 3.36	$ 4.88

Consolidated Statement Of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss) including noncontrolling interests	$ (23,251)	$ 14,774	$ 21,421
Other comprehensive income (loss) (net of income taxes)
Foreign exchange translation adjustment	1,916	1,735	(5,077)
Adjustment for foreign exchange translation (gain)/loss included in net income	14	0	196
Postretirement benefits reserves adjustment (excluding amortization)	30	(2,092)	280
Amortization and settlement of postretirement benefits reserves adjustment included in net periodic benefit costs	896	582	931
Total other comprehensive income (loss)	2,856	225	(3,670)
Comprehensive income (loss) including noncontrolling interests	(20,395)	14,999	17,751
Comprehensive income (loss) attributable to noncontrolling interests	(743)	588	174
Comprehensive income (loss) attributable to ExxonMobil	$ (19,652)	$ 14,411	$ 17,577

Consolidated Balance Sheet - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 4,364	$ 3,089
Notes and accounts receivable - net	20,581	26,966
Inventories
Crude oil, products and merchandise	14,169	14,010
Materials and supplies	4,681	4,518
Other current assets	1,098	1,469
Total current assets	44,893	50,052
Investments, advances and long-term receivables	43,515	43,164
Property, plant and equipment, at cost, less accumulated depreciation and depletion	227,553	253,018
Other assets, including intangibles - net	16,789	16,363
Total assets	332,750	362,597
Current liabilities
Notes and loans payable	20,458	20,578
Accounts payable and accrued liabilities	35,221	41,831
Income taxes payable	684	1,580
Total current liabilities	56,363	63,989
Long-term debt	47,182	26,342
Postretirement benefits reserves	22,415	22,304
Deferred income tax liabilities	18,165	25,620
Long-term obligations to equity companies	3,253	3,988
Other long-term obligations	21,242	21,416
Total liabilities	168,620	163,659
Commitments and contingencies
Equity
Common stock without par value (9,000 million shares authorized, 8,019 million shares issued)	15,688	15,637
Earnings reinvested	383,943	421,341
Accumulated other comprehensive income	(16,705)	(19,493)
Common stock held in treasury (3,786 million shares in 2020 and 3,785 million shares in 2019)	(225,776)	(225,835)
ExxonMobil share of equity	157,150	191,650
Noncontrolling interests	6,980	7,288
Total equity	164,130	198,938
Total liabilities and equity	$ 332,750	$ 362,597

Consolidated Balance Sheet (Parenthetical) - $ / shares shares in Millions	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Common stock, without par value
Common stock, shares authorized	9,000	9,000
Common stock, shares issued	8,019	8,019
Common stock held in treasury, shares	3,786	3,785

Consolidated Statement Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net income (loss) including noncontrolling interests	$ (23,251)	$ 14,774	$ 21,421
Adjustments for noncash transactions
Depreciation and depletion (includes impairments)	46,009	18,998	18,745
Deferred income tax charges/(credits)	(8,856)	(944)	(60)
Postretirement benefits expense in excess of/(less than) net payments	498	109	1,070
Other long-term obligation provisions in excess of/(less than) payments	(1,269)	(3,038)	(68)
Dividends received greater than/(less than) equity in current earnings of equity companies	979	(936)	(1,684)
Changes in operational working capital, excluding cash and debt
Reduction/(increase) - Notes and accounts receivable	5,384	(2,640)	(545)
Reduction/(increase) - Inventories	(315)	72	(3,107)
Reduction/(increase) - Other current assets	420	(234)	(25)
Increase/(reduction) - Accounts and other payables	(7,142)	3,725	2,321
Net (gain)/loss on asset sales	4	(1,710)	(1,993)
All other items - net	2,207	1,540	(61)
Net cash provided by operating activities	14,668	29,716	36,014
Cash flows from investing activities
Additions to property, plant and equipment	(17,282)	(24,361)	(19,574)
Proceeds associated with sales of subsidiaries, property, plant and equipment, and sales and returns of investments	999	3,692	4,123
Additional investments and advances	(4,857)	(3,905)	(1,981)
Other investing activities including collection of advances	2,681	1,490	986
Net cash used in investing activities	(18,459)	(23,084)	(16,446)
Cash flows from financing activities
Additions to long-term debt	23,186	7,052	46
Reductions in long-term debt	(8)	(1)	0
Reductions in short-term debt	(1,703)	(4,043)	(4,752)
Additions/(reductions) in commercial paper, and debt with three months or less maturity	(1,334)	5,654	(219)
Contingent consideration payments	(21)	0	0
Cash dividends to ExxonMobil shareholders	(14,865)	(14,652)	(13,798)
Cash dividends to noncontrolling interests	(188)	(192)	(243)
Changes in noncontrolling interests	623	158	146
Common stock acquired	(405)	(594)	(626)
Net cash provided by (used in) financing activities	5,285	(6,618)	(19,446)
Effects of exchange rate changes on cash	(219)	33	(257)
Increase/(decrease) in cash and cash equivalents	1,275	47	(135)
Cash and cash equivalents at beginning of year	3,089	3,042	3,177
Cash and cash equivalents at end of year	$ 4,364	$ 3,089	$ 3,042

Consolidated Statement Of Changes In Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock, without par value [Member]	ExxonMobil Share Of Earnings Reinvested [Member]	ExxonMobil Share Of Accumulated Other Comprehensive Income [Member]	ExxonMobil Share Of Common Stock Held In Treasury [Member]	ExxonMobil Share Of Equity [Member]	Noncontrolling Interest [Member]
Balance at Dec. 31, 2017	$ 194,500	$ 14,656	$ 414,540	$ (16,262)	$ (225,246)	$ 187,688	$ 6,812
Balance (in shares) - issued at Dec. 31, 2017	8,019
Balance (in shares) - in treasury at Dec. 31, 2017	(3,780)
Balance (in shares) - outstanding at Dec. 31, 2017	4,239
Amortization of stock-based awards	$ 758	758				758
Other	280	(156)				(156)	436
Net income (loss) for the year	21,421		20,840			20,840	581
Dividends - common shares (company)			(13,798)			(13,798)
Dividends - common shares (NCI)							(243)
Dividends - common shares (total)	(14,041)
Cumulative effect of accounting change	47		71	(39)		32	15
Other comprehensive income	(3,670)			(3,263)		(3,263)	(407)
Acquisitions, at cost (company)					(626)	(626)
Acquisitions, at cost (NCI)							(460)
Acquisitions, at cost (total)	$ (1,086)
Acquisitions (in shares)	(8)
Dispositions	$ 319				319	319
Dispositions (in shares)	6
Balance at Dec. 31, 2018	$ 198,528	15,258	421,653	(19,564)	(225,553)	191,794	6,734
Balance (in shares) - issued at Dec. 31, 2018	8,019
Balance (in shares) - in treasury at Dec. 31, 2018	(3,782)
Balance (in shares) - outstanding at Dec. 31, 2018	4,237
Amortization of stock-based awards	$ 697	697				697
Other	171	(318)				(318)	489
Net income (loss) for the year	14,774		14,340			14,340	434
Dividends - common shares (company)			(14,652)			(14,652)
Dividends - common shares (NCI)							(192)
Dividends - common shares (total)	(14,844)
Other comprehensive income	225			71		71	154
Acquisitions, at cost (company)					(594)	(594)
Acquisitions, at cost (NCI)							(331)
Acquisitions, at cost (total)	$ (925)
Acquisitions (in shares)	(8)
Dispositions	$ 312				312	312
Dispositions (in shares)	5
Balance at Dec. 31, 2019	$ 198,938	15,637	421,341	(19,493)	(225,835)	191,650	7,288
Balance (in shares) - issued at Dec. 31, 2019	8,019
Balance (in shares) - in treasury at Dec. 31, 2019	(3,785)
Balance (in shares) - outstanding at Dec. 31, 2019	4,234
Amortization of stock-based awards	$ 696	696				696
Other	47	(645)				(645)	692
Net income (loss) for the year	(23,251)		(22,440)			(22,440)	(811)
Dividends - common shares (company)			(14,865)			(14,865)
Dividends - common shares (NCI)							(188)
Dividends - common shares (total)	(15,053)
Cumulative effect of accounting change	(94)		(93)	0		(93)	(1)
Other comprehensive income	2,856			2,788		2,788	68
Acquisitions, at cost (company)					(405)	(405)
Acquisitions, at cost (NCI)							(68)
Acquisitions, at cost (total)	$ (473)
Acquisitions (in shares)	(8)
Dispositions	$ 464				464	464
Dispositions (in shares)	7
Balance at Dec. 31, 2020	$ 164,130	$ 15,688	$ 383,943	$ (16,705)	$ (225,776)	$ 157,150	$ 6,980
Balance (in shares) - issued at Dec. 31, 2020	8,019
Balance (in shares) - in treasury at Dec. 31, 2020	(3,786)
Balance (in shares) - outstanding at Dec. 31, 2020	4,233

Summary Of Accounting Policies	12 Months Ended
Summary Of Accounting Policies	Dec. 31, 2020
Accounting Policies [Abstract]
Summary Of Accounting Policies	Summary of Accounting Policies Principles of Consolidation and Accounting for Investments The Consolidated Financial Statements include the accounts of subsidiaries the Corporation controls. They also include the Corporation’s share of the undivided interest in certain upstream assets, liabilities, revenues and expenses. Amounts representing the Corporation’s interest in entities that it does not control, but over which it exercises significant influence, are included in “Investments, advances and long-term receivables”. The Corporation’s share of the net income of these companies is included in the Consolidated Statement of Income caption “Income from equity affiliates”. Majority ownership is normally the indicator of control that is the basis on which subsidiaries are consolidated. However, certain factors may indicate that a majority-owned investment is not controlled and therefore should be accounted for using the equity method of accounting. These factors occur where the minority shareholders are granted by law or by contract substantive participating rights. These include the right to approve operating policies, expense budgets, financing and investment plans, and management compensation and succession plans. Evidence of loss in value that might indicate impairment of investments in companies accounted for on the equity method is assessed to determine if such evidence represents a loss in value that is other than temporary. Examples of key indicators include a history of operating losses, negative earnings and cash flow outlook, significant downward revisions to oil and gas reserves, and the financial condition and prospects for the investee’s business segment or geographic region. If evidence of an other than temporary loss in fair value below carrying amount is determined, an impairment is recognized. In the absence of market prices for the investment, discounted cash flows are used to assess fair value. Investments in equity securities other than consolidated subsidiaries and equity method investments are measured at fair value with changes in fair value recognized in net income. The Corporation uses the modified approach for equity securities that do not have a readily determinable fair value. This modified approach measures investments at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions in a similar investment of the same issuer. The Corporation’s share of the cumulative foreign exchange translation adjustment for equity method investments is reported in “Accumulated other comprehensive income”. Revenue Recognition The Corporation generally sells crude oil, natural gas and petroleum and chemical products under short-term agreements at prevailing market prices. In some cases (e.g., natural gas), products may be sold under long-term agreements, with periodic price adjustments to reflect market conditions. Revenue is recognized at the amount the Corporation expects to receive when the customer has taken control, which is typically when title transfers and the customer has assumed the risks and rewards of ownership. The prices of certain sales are based on price indices that are sometimes not available until the next period. In such cases, estimated realizations are accrued when the sale is recognized, and are finalized when the price is available. Such adjustments to revenue from performance obligations satisfied in previous periods are not significant. Payment for revenue transactions is typically due within 30 days. Future volume delivery obligations that are unsatisfied at the end of the period are expected to be fulfilled through ordinary production or purchases. These performance obligations are based on market prices at the time of the transaction and are fully constrained due to market price volatility. Purchases and sales of inventory with the same counterparty that are entered into in contemplation of one another are combined and recorded as exchanges measured at the book value of the item sold. “Sales and other operating revenue” and “Notes and accounts receivable” primarily arise from contracts with customers. Long-term receivables are primarily from non-customers. Contract assets are mainly from marketing assistance programs and are not significant. Contract liabilities are mainly customer prepayments and accruals of expected volume discounts and are not significant. Income and Other Taxes The Corporation excludes from the Consolidated Statement of Income certain sales and value-added taxes imposed on and concurrent with revenue-producing transactions with customers and collected on behalf of governmental authorities. Similar taxes, for which the Corporation is not considered to be an agent for the government, are reported on a gross basis (included in both “Sales and other operating revenue” and “Other taxes and duties”). The Corporation accounts for U.S. tax on global intangible low-taxed income as an income tax expense in the period in which it is incurred. Derivative Instruments The Corporation may use derivative instruments for trading purposes and to offset exposures associated with commodity prices, foreign currency exchange rates and interest rates that arise from existing assets, liabilities, firm commitments and forecasted transactions. All derivative instruments, except those designated as normal purchase and normal sale, are recorded at fair value. Derivative assets and liabilities with the same counterparty are netted if the right of offset exists and certain other criteria are met. Collateral payables or receivables are netted against derivative assets and derivative liabilities, respectively. Recognition and classification of the gain or loss that results from adjusting a derivative to fair value depends on the purpose for the derivative. All gains and losses from derivative instruments for which the Corporation does not apply hedge accounting are immediately recognized in earnings. The Corporation may designate derivatives as fair value or cash flow hedges. For fair value hedges, the gain or loss from derivative instruments and the offsetting gain or loss from the hedged item are recognized in earnings. For cash flow hedges, the gain or loss from the derivative instrument is initially reported as a component of other comprehensive income and subsequently reclassified into earnings in the period that the forecasted transaction affects earnings. Fair Value Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Hierarchy Levels 1, 2 and 3 are terms for the priority of inputs to valuation techniques used to measure fair value. Hierarchy Level 1 inputs are quoted prices in active markets for identical assets or liabilities. Hierarchy Level 2 inputs are inputs other than quoted prices included within Level 1 that are directly or indirectly observable for the asset or liability. Hierarchy Level 3 inputs are inputs that are not observable in the market. Inventories Crude oil, products and merchandise inventories are carried at the lower of current market value or cost (generally determined under the last-in, first-out method – LIFO). Inventory costs include expenditures and other charges (including depreciation) directly and indirectly incurred in bringing the inventory to its existing condition and location. Selling expenses and general and administrative expenses are reported as period costs and excluded from inventory cost. Inventories of materials and supplies are valued at cost or less. Property, Plant and Equipment Cost Basis. The Corporation uses the “successful efforts” method to account for its exploration and production activities. Under this method, costs are accumulated on a field-by-field basis. Costs incurred to purchase, lease, or otherwise acquire a property (whether unproved or proved) are capitalized when incurred. Exploratory well costs are carried as an asset when the well has found a sufficient quantity of reserves to justify its completion as a producing well and where the Corporation is making sufficient progress assessing the reserves and the economic and operating viability of the project. Exploratory well costs not meeting these criteria are charged to expense. Other exploratory expenditures, including geophysical costs and annual lease rentals, are expensed as incurred. Development costs, including costs of productive wells and development dry holes, are capitalized. Depreciation, Depletion and Amortization. Depreciation, depletion and amortization are primarily determined under either the unit-of-production method or the straight-line method, which is based on estimated asset service life taking obsolescence into consideration. Acquisition costs of proved properties are amortized using a unit-of-production method, computed on the basis of total proved oil and natural gas reserve volumes. Capitalized exploratory drilling and development costs associated with productive depletable extractive properties are amortized using the unit-of-production rates based on the amount of proved developed reserves of oil and gas that are estimated to be recoverable from existing facilities using current operating methods. Under the unit-of-production method, oil and natural gas volumes are considered produced once they have been measured through meters at custody transfer or sales transaction points at the outlet valve on the lease or field storage tank. In the event that the unit-of-production method does not result in an equitable allocation of cost over the economic life of an upstream asset, an alternative method is used. The straight-line method is used in limited situations where the expected life of the asset does not reasonably correlate with that of the underlying reserves. For example, certain assets used in the production of oil and natural gas have a shorter life than the reserves, and as such, the Corporation uses straight-line depreciation to ensure the asset is fully depreciated by the end of its useful life. To the extent that proved reserves for a property are substantially de-booked and that property continues to produce such that the resulting depreciation charge does not result in an equitable allocation of cost over the expected life, assets will be depreciated using a unit-of-production method based on reserves determined at the most recent SEC price which results in a more meaningful quantity of proved reserves, appropriately adjusted for production and technical changes. Investments in refinery, chemical process, and lubes basestock manufacturing equipment are generally depreciated on a straight-line basis over a 25-year life. Service station buildings and fixed improvements generally are depreciated over a 20-year life. Maintenance and repairs, including planned major maintenance, are expensed as incurred. Major renewals and improvements are capitalized and the assets replaced are retired. Impairment Assessment. The Corporation tests assets or groups of assets for recoverability on an ongoing basis whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. Among the events or changes in circumstances which could indicate that the carrying value of an asset or asset group may not be recoverable are the following: •a significant decrease in the market price of a long-lived asset; •a significant adverse change in the extent or manner in which an asset is being used or in its physical condition including a significant decrease in current and projected reserve volumes; •a significant adverse change in legal factors or in the business climate that could affect the value, including an adverse action or assessment by a regulator; •an accumulation of project costs significantly in excess of the amount originally expected; •a current-period operating loss combined with a history and forecast of operating or cash flow losses; and •a current expectation that, more likely than not, a long-lived asset will be sold or otherwise disposed of significantly before the end of its previously estimated useful life. Asset valuation analysis, profitability reviews and other periodic control processes assist the Corporation in assessing whether events or changes in circumstances indicate the carrying amounts of any of its assets may not be recoverable. In general, the Corporation does not view temporarily low prices or margins as an indication of impairment. Management believes that prices over the long term must be sufficient to generate investments in energy supply to meet global demand. Although prices will occasionally drop significantly, industry prices over the long term will continue to be driven by market supply and demand fundamentals. On the supply side, industry production from mature fields is declining. This is being offset by investments to generate production from new discoveries, field developments and technology and efficiency advancements. OPEC investment activities and production policies also have an impact on world oil supplies. The demand side is largely a function of general economic activities and levels of prosperity. Because the lifespans of the vast majority of the Corporation’s major assets are measured in decades, the value of these assets is predominantly based on long-term views of future commodity prices and development and production costs. During the lifespan of these major assets, the Corporation expects that oil and gas prices will experience significant volatility, and consequently these assets will experience periods of higher earnings and periods of lower earnings, or even losses. In assessing whether events or changes in circumstances indicate the carrying value of an asset may not be recoverable, the Corporation considers recent periods of operating losses in the context of its longer-term view of prices. While near-term prices are subject to wide fluctuations, longer-term price views are more stable and meaningful for purposes of assessing future cash flows. When the industry experiences a prolonged and deep reduction in commodity prices, the market supply and demand conditions may result in changes to the Corporation’s price or margin assumptions it uses for its capital investment decisions. To the extent those changes result in a significant reduction to its oil price, natural gas price or margin ranges, the Corporation may consider that situation, in conjunction with other events or changes in circumstances such as a history of operating losses, an indicator of potential impairment for certain assets. In the Upstream, the standardized measure of discounted cash flows included in the Supplemental Information on Oil and Gas Exploration and Production Activities is required to use prices based on the average of first-of-month prices. These prices represent discrete points in time and could be higher or lower than the Corporation’s price assumptions which are used for impairment assessments. The Corporation believes the standardized measure does not provide a reliable estimate of the expected future cash flows to be obtained from the development and production of its oil and gas properties or of the value of its oil and gas reserves and therefore does not consider it relevant in determining whether events or changes in circumstances indicate the need for an impairment assessment. The Corporation has a robust process to monitor for indicators of potential impairment across its asset groups throughout the year. This process is aligned with the requirements of ASC 360 and ASC 932, and relies in part on the Corporation’s planning and budgeting cycle. If events or changes in circumstances indicate that the carrying value of an asset may not be recoverable, the Corporation estimates the future undiscounted cash flows of the affected properties to judge the recoverability of carrying amounts. In performing this assessment, assets are grouped at the lowest level for which there are identifiable cash flows that are largely independent of the cash flows of other groups of assets. Cash flows used in recoverability assessments are based on the Corporation’s assumptions which are developed in the annual planning and budgeting process, and are consistent with the criteria management uses to evaluate investment opportunities. These evaluations make use of the Corporation’s assumptions of future capital allocations, crude oil and natural gas commodity prices including price differentials, refining and chemical margins, volumes, development and operating costs, and foreign currency exchange rates. Volumes are based on projected field and facility production profiles, throughput, or sales. Management’s estimate of upstream production volumes used for projected cash flows makes use of proved reserve quantities and may include risk-adjusted unproved reserve quantities. Cash flow estimates for impairment testing exclude the effects of derivative instruments. An asset group is impaired if its estimated undiscounted cash flows are less than the asset’s carrying value. Impairments are measured by the amount by which the carrying value exceeds fair value. Fair value is based on market prices if an active market exists for the asset group, or discounted cash flows using a discount rate commensurate with the risk. Unproved properties are assessed periodically to determine whether they have been impaired. Significant unproved properties are assessed for impairment individually, and valuation allowances against the capitalized costs are recorded based on the Corporation's future development plans, the estimated economic chance of success and the length of time that the Corporation expects to hold the properties. Properties that are not individually significant are aggregated by groups and amortized based on development risk and average holding period. Other. Gains on sales of proved and unproved properties are only recognized when there is neither uncertainty about the recovery of costs applicable to any interest retained nor any substantial obligation for future performance by the Corporation. Losses on properties sold are recognized when incurred or when the properties are held for sale and the fair value of the properties is less than the carrying value. Interest costs incurred to finance expenditures during the construction phase of multiyear projects are capitalized as part of the historical cost of acquiring the constructed assets. The project construction phase commences with the development of the detailed engineering design and ends when the constructed assets are ready for their intended use. Capitalized interest costs are included in property, plant and equipment and are depreciated over the service life of the related assets. Environmental Liabilities Liabilities for environmental costs are recorded when it is probable that obligations have been incurred and the amounts can be reasonably estimated. These liabilities are not reduced by possible recoveries from third parties, and projected cash expenditures are not discounted. Foreign Currency Translation The Corporation selects the functional reporting currency for its international subsidiaries based on the currency of the primary economic environment in which each subsidiary operates. Downstream and Chemical operations primarily use the local currency. However, the U.S. dollar is used in countries with a history of high inflation (primarily in Latin America) and Singapore, which predominantly sells into the U.S. dollar export market. Upstream operations which are relatively self-contained and integrated within a particular country, such as Canada, the United Kingdom and continental Europe, use the local currency. Some Upstream operations, primarily in Asia and Africa, use the U.S. dollar because they predominantly sell crude and natural gas production into U.S. dollar-denominated markets. For all operations, gains or losses from remeasuring foreign currency transactions into the functional currency are included in income.

Accounting Changes

12 Months Ended

Dec. 31, 2020

New Accounting Pronouncements and Changes in Accounting Principles [Abstract]

Accounting Changes

Effective January 1, 2020, the Corporation adopted the Financial Accounting Standards Board’s update, Financial Instruments – Credit Losses (Topic 326), as amended. The standard requires a valuation allowance for credit losses be recognized for certain financial assets that reflects the current expected credit loss over the asset’s contractual life. The valuation allowance considers the risk of loss, even if remote, and considers past events, current conditions and reasonable and supportable forecasts. The standard requires this expected loss methodology for trade receivables, certain other financial assets and off-balance sheet credit exposures. The cumulative effect adjustment related to the adoption of this standard reduced ExxonMobil's share of equity by $93 million.

The Corporation is exposed to credit losses primarily through sales of petroleum products, crude oil, natural gas liquids and natural gas, as well as loans to equity companies and joint venture receivables. A counterparty’s ability to pay is assessed through a credit review process that considers payment terms, the counterparty’s established credit rating or the Corporation’s assessment of the counterparty’s credit worthiness, contract terms, country of operation, and other risks. The Corporation can require prepayment or collateral to mitigate certain credit risks.

The Corporation groups financial assets into portfolios that share similar risk characteristics for purposes of determining the allowance for credit losses and assesses if a significant change in the risk of credit loss has occurred. Among the quantitative and qualitative factors considered are historical financial data, current conditions, industry and country risk, current credit ratings and the quality of third-party guarantees secured from the counterparty. Financial assets are written off in whole, or in part, when practical recovery efforts have been exhausted and no reasonable expectation of recovery exists. Subsequent recoveries of amounts previously written off are recognized in earnings. The Corporation manages receivable portfolios using past due balances as a key credit quality indicator.

The Corporation recognizes a credit allowance for off-balance sheet credit exposures as a liability on the balance sheet, separate from the allowance for credit losses related to recognized financial assets. Among these exposures are unfunded loans to equity companies and financial guarantees that cannot be cancelled unilaterally by the Corporation.


	Allowance for Current Expected Credit Losses
	Notes and Accounts Receivable		Advances and Long-Term Receivables	Liabilities for Off- Balance Sheet Assets
	Trade	Other			Total
	(millions of dollars)
Balance at December 31, 2019	34	56	413	—	503
Cumulative effect of accounting change	52	6	39	12	109
Current period provision	9	15	(9)	(1)	14
Write-offs charged against the allowance	(2)	(3)	—	—	(5)
Other	2	(3)	3	—	2
Balance at December 31, 2020	95	71	446	11	623

Balance at December 31, 2020
Financial Assets subject to credit losses standard - net	16,250	1,962	9,447

Miscellaneous Financial Information

12 Months Ended

Dec. 31, 2020

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Miscellaneous Financial Information

Research and development expenses totaled $1,016 million in 2020, $1,214 million in 2019, and $1,116 million in 2018.

Net income included before-tax aggregate foreign exchange transaction losses of $24 million, $104 million and $138 million in 2020, 2019 and 2018, respectively.

In 2020, 2019, and 2018, net income included gains of $41 million, $523 million, and $107 million, respectively, attributable to the combined effects of LIFO inventory accumulations and drawdowns. The aggregate replacement cost of inventories was estimated to exceed their LIFO carrying values by $5.4 billion and $9.7 billion at December 31, 2020, and 2019, respectively.

Crude oil, products and merchandise as of year-end 2020 and 2019 consist of the following:


	Dec 31, 2020	Dec 31, 2019
	(millions of dollars)
Crude oil	5,354	5,111
Petroleum products	5,138	5,281
Chemical products	3,023	3,240
Gas/other	654	378
Total	14,169	14,010

Mainly as a result of declines in prices for crude oil, natural gas and petroleum products in 2020 and a significant decline in its market capitalization at the end of the first quarter, the Corporation recognized before-tax goodwill impairment charges of $611 million in Upstream, Downstream, and Chemical reporting units. Fair value of the goodwill reporting units primarily reflected market-based estimates of historical EBITDA multiples at the end of the first quarter. Charges related to goodwill impairments are included in “Depreciation and depletion” on the Statement of Income.

Other Comprehensive Income Information

12 Months Ended

Dec. 31, 2020

Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]

Other Comprehensive Income Information


ExxonMobil Share of Accumulated Other Comprehensive Income	Cumulative Foreign Exchange Translation Adjustment	Postretirement Benefits Reserves Adjustment	Total
	(millions of dollars)
Balance as of December 31, 2017	(9,482)	(6,780)	(16,262)
Current period change excluding amounts reclassified from accumulated other comprehensive income	(4,595)	201	(4,394)
Amounts reclassified from accumulated other comprehensive income	196	896	1,092
Total change in accumulated other comprehensive income	(4,399)	1,097	(3,302)
Balance as of December 31, 2018	(13,881)	(5,683)	(19,564)

Current period change excluding amounts reclassified from accumulated other comprehensive income	1,435	(1,927)	(492)
Amounts reclassified from accumulated other comprehensive income	—	563	563
Total change in accumulated other comprehensive income	1,435	(1,364)	71
Balance as of December 31, 2019	(12,446)	(7,047)	(19,493)

Current period change excluding amounts reclassified from accumulated other comprehensive income (1)	1,818	95	1,913
Amounts reclassified from accumulated other comprehensive income	14	861	875
Total change in accumulated other comprehensive income	1,832	956	2,788
Balance as of December 31, 2020	(10,614)	(6,091)	(16,705)

(1) Cumulative Foreign Exchange Translation Adjustment includes net investment hedge gain/(loss) of $(355) million, net of taxes.


Amounts Reclassified Out of Accumulated Other Comprehensive Income - Before-tax Income/(Expense)	2020	2019	2018
	(millions of dollars)
Foreign exchange translation gain/(loss) included in net income (Statement of Income line: Other income)	(14)	—	(196)
Amortization and settlement of postretirement benefits reserves adjustment included in net periodic benefit costs (Statement of Income line: Non-service pension and postretirement benefit expense)	(1,158)	(751)	(1,208)


Income Tax (Expense)/Credit For Components of Other Comprehensive Income	2020	2019	2018
	(millions of dollars)
Foreign exchange translation adjustment	118	88	32
Postretirement benefits reserves adjustment (excluding amortization)	109	719	(193)
Amortization and settlement of postretirement benefits reserves adjustment included in net periodic benefit costs	(262)	(169)	(277)
Total	(35)	638	(438)

Cash Flow Information

12 Months Ended

Dec. 31, 2020

Supplemental Cash Flow Information [Abstract]

Cash Flow Information

The Consolidated Statement of Cash Flows provides information about changes in cash and cash equivalents. Highly liquid investments with maturities of three months or less when acquired are classified as cash equivalents.

For 2020, the “Depreciation and depletion” and “Deferred income tax charges/(credits)” on the Consolidated Statement of Cash Flows includes impacts from asset impairments, primarily in Upstream.

For 2019, the “Net (gain)/loss on asset sales” on the Consolidated Statement of Cash Flows includes before-tax amounts from the sale of non-operated upstream assets in Norway and upstream asset transactions in the U.S. The Norway assets were sold for $4.5 billion, resulting in a gain of $3.7 billion and cash proceeds of $3.1 billion in 2019. For 2018, the number includes before-tax amounts from the sale of service stations in Germany, the divestment of the Augusta refinery in Italy, and the sale of an undeveloped upstream property in Australia. These net gains are reported in “Other income” on the Consolidated Statement of Income.

In 2020, the “Additions/(reductions) in commercial paper, and debt with three months or less maturity” on the Consolidated Statement of Cash Flows includes a net $8.4 billion addition of commercial paper with maturity over three months. The gross amount issued was $35.4 billion, while the gross amount repaid was $27.0 billion. In 2019, the number includes a net $4.6 billion addition of commercial paper with maturity over three months. The gross amount issued was $18.9 billion, while the gross amount repaid was $14.3 billion. In 2018, the number includes a net $275 million addition of commercial paper with maturity over three months. The gross amount issued was $4.0 billion, while the gross amount repaid was $3.8 billion.


	2020	2019	2018
	(millions of dollars)
Income taxes paid	2,428	7,018	9,294
Cash interest paid
Included in cash flows from operating activities	786	560	303
Capitalized, included in cash flows from investing activities	665	731	652
Total cash interest paid	1,451	1,291	955

Additional Working Capital Information

12 Months Ended

Dec. 31, 2020

Additional Working Capital Information [Abstract]

Additional Working Capital Information


	Dec 31, 2020	Dec 31, 2019
	(millions of dollars)
Notes and accounts receivable
Trade, less reserves of $96 million and $34 million	16,339	21,100
Other, less reserves of $378 million and $371 million	4,242	5,866
Total	20,581	26,966
Notes and loans payable
Bank loans	222	316
Commercial paper	17,306	18,561
Long-term debt due within one year	2,930	1,701
Total	20,458	20,578
Accounts payable and accrued liabilities
Trade payables	17,499	24,694
Payables to equity companies	6,476	6,825
Accrued taxes other than income taxes	3,408	3,301
Other	7,838	7,011
Total	35,221	41,831

The Corporation has short-term committed lines of credit of $11.3 billion which were unused as of December 31, 2020. These lines are available for general corporate purposes.

The weighted-average interest rate on short-term borrowings outstanding was 0.2 percent and 1.7 percent at December 31, 2020, and 2019, respectively.

Equity Company Information

12 Months Ended

Dec. 31, 2020

Equity Method Investment, Financial Statement, Reported Amounts [Abstract]

Equity Company Information

The summarized financial information below includes amounts related to certain less-than-majority-owned companies and majority-owned subsidiaries where minority shareholders possess the right to participate in significant management decisions (see Note 1). These companies are primarily engaged in oil and gas exploration and production, and natural gas marketing in North America; natural gas exploration, production and distribution in Europe; liquefied natural gas (LNG) operations and transportation of crude oil in Africa; and exploration, production, LNG operations, and the manufacture and sale of petroleum and petrochemical products in Asia and the Middle East. Also included are several refining, petrochemical manufacturing and marketing ventures.

The share of total equity company revenues from sales to ExxonMobil consolidated companies was 11 percent, 13 percent and 14 percent in the years 2020, 2019 and 2018, respectively.

The Corporation’s ownership in these ventures is in the form of shares in corporate joint ventures as well as interests in partnerships. Differences between the company’s carrying value of an equity investment and its underlying equity in the net assets of the affiliate are assigned to the extent practicable to specific assets and liabilities based on the company’s analysis of the factors giving rise to the difference. The amortization of this difference, as appropriate, is included in “Income from equity affiliates” on the Consolidated Statement of Income.

Impairments related to U.S. upstream equity investments of $600 million are included in “Income from equity affiliates” on the Consolidated Statement of Income.


	2020		2019		2018
Equity Company Financial Summary	Total	ExxonMobil Share	Total	ExxonMobil Share	Total	ExxonMobil Share
	(millions of dollars)
Total revenues	69,954	21,282	102,365	31,240	112,938	34,539
Income before income taxes	12,743	2,830	29,424	7,927	37,203	10,482
Income taxes	4,333	870	9,725	2,500	11,568	3,151
Income from equity affiliates	8,410	1,960	19,699	5,427	25,635	7,331

Current assets	33,419	11,969	36,035	12,661	38,670	13,394
Long-term assets	150,358	41,457	143,321	40,001	128,830	35,970
Total assets	183,777	53,426	179,356	52,662	167,500	49,364
Current liabilities	18,827	5,245	24,583	6,939	27,324	7,606
Long-term liabilities	66,053	19,927	61,022	18,158	56,913	17,109
Net assets	98,897	28,254	93,751	27,565	83,263	24,649

A list of significant equity companies as of December 31, 2020, together with the Corporation’s percentage ownership interest, is detailed below:


			Percentage Ownership Interest
Upstream
Aera Energy LLC			48
Barzan Gas Company Limited			7
BEB Erdgas und Erdoel GmbH & Co. KG			50
Cameroon Oil Transportation Company S.A.			41
Caspian Pipeline Consortium - Kazakhstan			8
CORAL FLNG, S.A.			25
Cross Timbers Energy, LLC			50
Golden Pass LNG Terminal LLC			30
Golden Pass Pipeline LLC			30
Marine Well Containment Company LLC			10
Mozambique Rovuma Venture, S.p.A.			36
Nederlandse Aardolie Maatschappij B.V.			50
Papua New Guinea Liquefied Natural Gas Global Company LDC			33
Permian Highway Pipeline LLC			20
Qatar Liquefied Gas Company Limited			10
Qatar Liquefied Gas Company Limited (2)			24
Ras Laffan Liquefied Natural Gas Company Limited			25
Ras Laffan Liquefied Natural Gas Company Limited (II)			31
Ras Laffan Liquefied Natural Gas Company Limited (3)			30
South Hook LNG Terminal Company Limited			24
Tengizchevroil, LLP			25
Terminale GNL Adriatico S.r.l.			71

Downstream
Alberta Products Pipe Line Ltd.			45
Fujian Refining & Petrochemical Co. Ltd.			25
Permian Express Partners LLC			12
Saudi Aramco Mobil Refinery Company Ltd.			50

Chemical
Al-Jubail Petrochemical Company			50
Gulf Coast Growth Ventures LLC			50
Saudi Yanbu Petrochemical Co.			50

Investments, Advances And Long-Term Receivables

12 Months Ended

Dec. 31, 2020

Long-term Investments and Receivables, Net [Abstract]

Investments, Advances And Long-Term Receivables

Investments, Advances and Long-Term Receivables


	Dec 31, 2020	Dec 31, 2019
	(millions of dollars)
Equity method company investments and advances
Investments	29,772	29,291
Advances, net of allowances of $31 million in 2020	8,812	8,542
Total equity method company investments and advances	38,584	37,833
Equity securities carried at fair value and other investments at adjusted cost basis	143	190
Long-term receivables and miscellaneous, net of reserves of $6,115 million and $5,643 million	4,788	5,141
Total	43,515	43,164

Property, Plant And Equipment And Asset Retirement Obligations

12 Months Ended

Dec. 31, 2020

Property, Plant And Equipment And Asset Retirement Obligations [Abstract]

Property, Plant And Equipment And Asset Retirement Obligations

Property, Plant and Equipment and Asset Retirement Obligations


	December 31, 2020		December 31, 2019
Property, Plant and Equipment	Cost	Net	Cost	Net
	(millions of dollars)
Upstream	386,614	167,472	376,041	196,767
Downstream	57,922	27,716	52,527	24,506
Chemical	42,868	21,924	40,788	21,260
Other	17,918	10,441	17,346	10,485
Total	505,322	227,553	486,702	253,018

The Corporation has a robust process to monitor for indicators of potential impairment across its asset groups throughout the year. This process is aligned with the requirements of ASC 360 and ASC 932, and relies in part on the Corporation’s planning and budgeting cycle. In 2020, the Corporation identified a number of situations where events or changes in circumstances indicated that the carrying value of certain long-lived assets may not be recoverable. Those situations primarily related to the annual review and approval of the Corporation's business and strategic plan. As part of the planning process, the Corporation assessed its full portfolio to prioritize assets with the highest future value potential within its broad range of available opportunities in order to optimize resources within current levels of debt and operating cash flow, as well as identify potential asset divestment candidates. This effort included a re-assessment of dry gas assets, primarily in North America, which previously had been included in the Corporation’s future development plans. Under the plan as approved, the Corporation no longer plans to develop a significant portion of its dry gas portfolio, including a portion of its resources in the Appalachian, Rocky Mountains, Oklahoma, Texas, Louisiana, and Arkansas regions of the U.S., as well as resources in Western Canada and Argentina. The decision not to develop these assets resulted in non-cash, before-tax charges of $24.4 billion in Upstream to reduce the carrying value of those assets to fair value. Other before-tax impairment charges in 2020 included $0.9 billion in Upstream, $0.5 billion in Downstream, and $0.1 billion in Chemical. Impairment charges are primarily recognized in the lines “Depreciation and depletion” and “Exploration expenses, including dry holes” on the Consolidated Statement of Income.

The assessment of fair value requires the use of Level 3 inputs and assumptions that are based upon the views of a likely market participant. The principal parameters used to establish fair value include estimates of acreage values and flowing production metrics from comparable market transactions, market-based estimates of historical cash flow multiples, and discounted cash flows. Inputs and assumptions used in discounted cash flow models include estimates of future production volumes, commodity prices which were consistent with the average of third-party industry experts and government agencies, drilling and development costs, and discount rates ranging from 6 percent to 8 percent which are reflective of the characteristics of the asset group.

Factors which could put further assets at risk of impairment in the future include reductions in the Corporation’s price outlooks, changes in the allocation of capital, and operating cost increases which exceed the pace of efficiencies or the pace of oil and natural gas price increases. However, due to the inherent difficulty in predicting future commodity prices, and the relationship between industry prices and costs, it is not practicable to reasonably estimate the existence or range of any potential future impairment charges related to the Corporation’s long-lived assets. In 2019 and 2018, the before-tax impairment charges were $0.1 billion and $0.7 billion, respectively.

Accumulated depreciation and depletion totaled $277,769 million at the end of 2020 and $233,684 million at the end of 2019. Interest capitalized in 2020, 2019 and 2018 was $665 million, $731 million and $652 million, respectively.

Asset Retirement Obligations

The Corporation incurs retirement obligations for certain assets. The fair values of these obligations are recorded as liabilities on a discounted basis, which is typically at the time the assets are installed. In the estimation of fair value, the Corporation uses assumptions and judgments regarding such factors as the existence of a legal obligation for an asset retirement obligation; technical assessments of the assets; estimated amounts and timing of settlements; discount rates; and inflation rates. Asset retirement obligations incurred in the current period were Level 3 fair value measurements. The costs associated with these liabilities are capitalized as part of the related assets and depreciated as the reserves are produced. Over time, the liabilities are accreted for the change in their present value.

Asset retirement obligations for downstream and chemical facilities generally become firm at the time the facilities are permanently shut down and dismantled. These obligations may include the costs of asset disposal and additional soil remediation. However, these sites have indeterminate lives based on plans for continued operations and as such, the fair value of the conditional legal obligations cannot be measured, since it is impossible to estimate the future settlement dates of such obligations.

The following table summarizes the activity in the liability for asset retirement obligations:


	2020	2019	2018
	(millions of dollars)
Balance at January 1	11,280	12,103	12,705
Accretion expense and other provisions	584	649	681
Reduction due to property sales	(77)	(1,085)	(333)
Payments made	(669)	(827)	(600)
Liabilities incurred	26	89	46
Foreign currency translation	239	84	(481)
Revisions	(136)	267	85
Balance at December 31	11,247	11,280	12,103

The long-term Asset Retirement Obligations were $10,558 million and $10,279 million at December 31, 2020, and 2019, respectively, and are included in “Other long-term obligations.”

Accounting For Suspended Exploratory Well Costs

12 Months Ended

Dec. 31, 2020

Capitalized Exploratory Well Costs [Abstract]

Accounting For Suspended Exploratory Well Costs

Accounting for Suspended Exploratory Well Costs

The Corporation continues capitalization of exploratory well costs when the well has found a sufficient quantity of reserves to justify its completion as a producing well and the Corporation is making sufficient progress assessing the reserves and the economic and operating viability of the project. The term “project” as used in this report can refer to a variety of different activities and does not necessarily have the same meaning as in any government payment transparency reports.

The following two tables provide details of the changes in the balance of suspended exploratory well costs as well as an aging summary of those costs.

Change in capitalized suspended exploratory well costs:


	2020	2019	2018
	(millions of dollars)
Balance beginning at January 1	4,613	4,160	3,700
Additions pending the determination of proved reserves	208	532	564
Charged to expense	(318)	(46)	(7)
Reclassifications to wells, facilities and equipment based on the determination of proved reserves	(174)	(37)	(48)
Divestments/Other	53	4	(49)
Ending balance at December 31	4,382	4,613	4,160
Ending balance attributed to equity companies included above	306	306	306

Period end capitalized suspended exploratory well costs:


	2020	2019	2018
	(millions of dollars)
Capitalized for a period of one year or less	208	532	564
Capitalized for a period of between one and five years	1,828	2,206	2,028
Capitalized for a period of between five and ten years	1,932	1,411	1,150
Capitalized for a period of greater than ten years	414	464	418
Capitalized for a period greater than one year - subtotal	4,174	4,081	3,596
Total	4,382	4,613	4,160

Exploration activity often involves drilling multiple wells, over a number of years, to fully evaluate a project. The table below provides a breakdown of the number of projects with only exploratory well costs capitalized for a period of one year or less and those that have had exploratory well costs capitalized for a period greater than one year.


	2020	2019	2018
Number of projects that only have exploratory well costs capitalized for a period of one year or less	3	4	6
Number of projects that have exploratory well costs capitalized for a period greater than one year	34	46	52
Total	37	50	58

Of the 34 projects that have exploratory well costs capitalized for a period greater than one year as of December 31, 2020, 13 projects have drilling in the preceding year or exploratory activity planned in the next two years, while the remaining 21 projects are those with completed exploratory activity progressing toward development.

The table below provides additional detail for those 21 projects, which total $3,181 million.


Country/Project	Dec. 31, 2020	Years Wells Drilled / Acquired			Comment
(millions of dollars)
Angola
–Kaombo Split Hub Phase 2	10	2006			Evaluating development plan to tie into planned production facilities.
Argentina
–La Invernada	72	2014			Evaluating development plan to tie into planned infrastructure.
Australia
–Gorgon Area Ullage	347	1994	-	2015	Evaluating development plans to tie into existing LNG facilities.
Brazil
–Bacalhau Phase 1	284	2018			Continuing discussions with the government regarding development plan.
Canada
–Hibernia North	26	2019			Awaiting capacity in existing/planned infrastructure.
Iraq
–Kurdistan Pirmam	109	2015			Evaluating commercialization alternatives, while waiting for government approval to enter Gas Holding Period.
Kazakhstan
–Kairan	53	2004	-	2007	Evaluating commercialization and field development alternatives, while continuing discussions with the government regarding the development plan.
Mozambique
–Rovuma LNG Future Non-Straddling Train	120	2017			Evaluating/progressing development plan to tie into planned LNG facilities.
–Rovuma LNG Phase 1	150	2017			Progressing development plan to tie into planned LNG facilities.
–Rovuma LNG Unitized Trains	35	2017			Evaluating/progressing development plan to tie into planned LNG facilities.
Nigeria
–Bonga North	34	2004	-	2009	Evaluating/progressing development plan for tieback to existing/planned infrastructure.
–Bonga SW	3	2001			Evaluating/progressing development plan for tieback to existing/planned infrastructure.
–Bosi	79	2002	-	2006	Development activity under way, while continuing discussions with the government regarding development plan.
–Owowo	67	2009	-	2016	Evaluating development plan for tieback to existing production facilities.
–Pegi	32	2009			Awaiting capacity in existing/planned infrastructure.
–Ukot SW	41	2014			Evaluating development plan for tieback to existing production facilities.
Papua New Guinea
–Papua LNG	246	2017			Evaluating/progressing development plans.
–P'nyang	116	2012	-	2018	Evaluating/progressing development plans.
Romania
–Neptun Deep	536	2012	-	2016	Continuing discussions with the government regarding development plan.
Tanzania
–Tanzania Block 2	525	2012	-	2015	Evaluating development alternatives, while continuing discussions with the government regarding development plan.
Vietnam
–Blue Whale	296	2011	-	2015	Evaluating/progressing development plans.
Total 2020 (21 projects)	3,181

Leases

12 Months Ended

Dec. 31, 2020

Lessee Disclosure [Abstract]

Leases

The Corporation and its consolidated affiliates generally purchase the property, plant and equipment used in operations, but there are situations where assets are leased, primarily for drilling equipment, tankers, office buildings, railcars, and other moveable equipment. Right of use assets and lease liabilities are established on the balance sheet for leases with an expected term greater than one year by discounting the amounts fixed in the lease agreement for the duration of the lease which is reasonably certain, considering the probability of exercising any early termination and extension options. The portion of the fixed payment related to service costs for drilling equipment, tankers and finance leases is excluded from the calculation of right of use assets and lease liabilities. Generally, assets are leased only for a portion of their useful lives, and are accounted for as operating leases. In limited situations assets are leased for nearly all of their useful lives, and are accounted for as finance leases.

Variable payments under these lease agreements are not significant. Residual value guarantees, restrictions, or covenants related to leases, and transactions with related parties are also not significant. In general, leases are capitalized using the incremental borrowing rate of the leasing affiliate. The Corporation’s activities as a lessor are not significant.


	Operating Leases
	Drilling Rigs and Related Equipment	Other	Total	Finance Leases
	(millions of dollars)
Lease Cost	2020
Operating lease cost	297	1,256	1,553
Short-term and other (net of sublease rental income)	530	1,083	1,613
Amortization of right of use assets				143
Interest on lease liabilities				169
Total	827	2,339	3,166	312


	Operating Leases
	Drilling Rigs and Related Equipment	Other	Total	Finance Leases
	(millions of dollars)
Lease Cost	2019
Operating lease cost	238	1,196	1,434
Short-term and other (net of sublease rental income)	926	1,116	2,042
Amortization of right of use assets				121
Interest on lease liabilities				133
Total	1,164	2,312	3,476	254


	Operating Leases
	Drilling Rigs and Related Equipment		Other		Total		Finance Leases
	(millions of dollars)
Balance Sheet	December 31, 2020
Right of use assets
Included in Other assets, including intangibles - net	834		5,244		6,078
Included in Property, plant and equipment - net							2,188
Total right of use assets	834		5,244		6,078		2,188

Lease liability due within one year
Included in Accounts payable and accrued liabilities	243		925		1,168		4
Included in Notes and loans payable							102
Long-term lease liability
Included in Other long-term obligations	589		3,405		3,994
Included in Long-term debt							1,680
Included in Long-term obligations to equity companies							135
Total lease liability	832		4,330		5,162		1,921

Weighted average remaining lease term - years	5		12		11		20
Weighted average discount rate - percent	2.2	%	3.0	%	2.9	%	8.9	%


	Operating Leases
	Drilling Rigs and Related Equipment		Other		Total		Finance Leases
	(millions of dollars)
Balance Sheet	December 31, 2019
Right of use assets
Included in Other assets, including intangibles - net	572		6,061		6,633
Included in Property, plant and equipment - net							1,997
Total right of use assets	572		6,061		6,633		1,997

Lease liability due within one year
Included in Accounts payable and accrued liabilities	221		990		1,211		15
Included in Notes and loans payable							84
Long-term lease liability
Included in Other long-term obligations	330		4,152		4,482
Included in Long-term debt							1,670
Included in Long-term obligations to equity companies							139
Total lease liability	551		5,142		5,693		1,908

Weighted average remaining lease term - years	4		11		10		20
Weighted average discount rate - percent	3.1	%	3.2	%	3.2	%	9.7	%


	Operating Leases
	Drilling Rigs and Related Equipment	Other	Total	Finance Leases
	(millions of dollars)
Maturity Analysis of Lease Liabilities	December 31, 2020
2021	259	1,031	1,290	268
2022	256	817	1,073	259
2023	97	482	579	252
2024	71	387	458	247
2025	71	342	413	240
2026 and beyond	124	2,157	2,281	2,544
Total lease payments	878	5,216	6,094	3,810
Discount to present value	(46)	(886)	(932)	(1,889)
Total lease liability	832	4,330	5,162	1,921

In addition to the lease liabilities in the table immediately above, at December 31, 2020, undiscounted commitments for leases not yet commenced totaled $445 million for operating leases and $4,109 million for finance leases. The finance leases relate to floating production storage and offloading vessels, LNG transportation vessels, and a long-term hydrogen purchase agreement. The underlying assets for these finance leases were primarily designed by, and are being constructed by, the lessors.


	Operating Leases
	Drilling Rigs and Related Equipment	Other	Total	Finance Leases
	(millions of dollars)
Other Information	2020
Cash paid for amounts included in the measurement of lease liabilities
Cash flows from operating activities		1,159	1,159	31
Cash flows from investing activities	283		283
Cash flows from financing activities				94

Noncash right of use assets recorded in exchange for lease liabilities	552	183	735	108


	Operating Leases
	Drilling Rigs and Related Equipment	Other	Total	Finance Leases
	(millions of dollars)
Other Information	2019
Cash paid for amounts included in the measurement of lease liabilities
Cash flows from operating activities		1,116	1,116	54
Cash flows from investing activities	258		258
Cash flows from financing activities				177

Noncash right of use assets recorded for lease liabilities
For January 1 adoption of ASC 842	445	2,818	3,263
In exchange for lease liabilities during the period	350	3,313	3,663	422

Disclosures under the previous lease standard (ASC 840)

Net rental cost incurred under both cancelable and noncancelable operating leases was $2,715 million in 2018.

Earnings Per Share

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Earnings Per Share


Earnings per common share	2020	2019	2018
Net income (loss) attributable to ExxonMobil (millions of dollars)	(22,440)	14,340	20,840

Weighted average number of common shares outstanding (millions of shares)	4,271	4,270	4,270

Earnings (Loss) per common share (dollars) (1)	(5.25)	3.36	4.88

Dividends paid per common share (dollars)	3.48	3.43	3.23

(1)The earnings (loss) per common share and earnings (loss) per common share - assuming dilution are the same in each period shown.

Financial Instruments And Derivatives

12 Months Ended

Dec. 31, 2020

Financial Instruments And Derivatives [Abstract]

Financial Instruments And Derivatives

Financial Instruments and Derivatives

Financial Instruments. The estimated fair value of financial instruments at December 31, 2020 and December 31, 2019, and the related hierarchy level for the fair value measurement is as follows:


	At December 31, 2020
	(millions of dollars)
	Fair Value
	Level 1	Level 2	Level 3	Total Gross Assets & Liabilities	Effect of Counterparty Netting	Effect of Collateral Netting	Difference in Carrying Value and Fair Value	Net Carrying Value
Assets
Derivative assets (1)	1,247	194	—	1,441	(1,282)	(6)	—	153
Advances to/receivables from equity companies (2)(6)	—	3,275	5,904	9,179	—	—	(367)	8,812
Other long-term financial assets (3)	1,235	—	944	2,179	—	—	125	2,304

Liabilities
Derivative liabilities (4)	1,443	254	—	1,697	(1,282)	(202)	—	213
Long-term debt (5)	50,263	125	4	50,392	—	—	(4,890)	45,502
Long-term obligations to equity companies (6)	—	—	3,530	3,530	—	—	(277)	3,253
Other long-term financial liabilities (7)	—	—	964	964	—	—	44	1,008


	At December 31, 2019
	(millions of dollars)
	Fair Value
	Level 1	Level 2	Level 3	Total Gross Assets & Liabilities	Effect of Counterparty Netting	Effect of Collateral Netting	Difference in Carrying Value and Fair Value	Net Carrying Value
Assets
Derivative assets (1)	533	102	—	635	(463)	(70)	—	102
Advances to/receivables from equity companies (2)(6)	—	1,941	6,729	8,670	—	—	(128)	8,542
Other long-term financial assets (3)	1,145	—	974	2,119	—	—	44	2,163

Liabilities
Derivative liabilities (4)	568	70	—	638	(463)	(105)	—	70
Long-term debt (5)	25,652	134	3	25,789	—	—	(1,117)	24,672
Long-term obligations to equity companies (6)	—	—	4,245	4,245	—	—	(257)	3,988
Other long-term financial liabilities (7)	—	—	1,042	1,042	—	—	16	1,058

(1)Included in the Balance Sheet lines: Notes and accounts receivable - net and Other assets, including intangibles - net

(2)Included in the Balance Sheet line: Investments, advances and long-term receivables

(3)Included in the Balance Sheet lines: Investments, advances and long term receivables and Other assets, including intangibles - net

(4)Included in the Balance Sheet lines: Accounts payable and accrued liabilities and Other long-term obligations

(5)Excluding finance lease obligations

(6)Advances to/receivables from equity companies and long-term obligations to equity companies are mainly designated as hierarchy level 3 inputs. The fair value is calculated by discounting the remaining obligations by a rate consistent with the credit quality and industry of the company.

(7)Included in the Balance Sheet line: Other long-term obligations. Includes contingent consideration related to a prior year acquisition where fair value is based on expected drilling activities and discount rates.

The increase in the estimated fair value and book value of long-term debt reflects the Corporation’s issuance of $23 billion of long-term debt during 2020.

At December 31, 2020 and December 31, 2019, the Corporation had $504 million and $379 million of collateral under master netting arrangements not offset against the derivatives on the Consolidated Balance Sheet, primarily related to initial margin requirements.

Derivative Instruments. The Corporation’s size, strong capital structure, geographic diversity and the complementary nature of the Upstream, Downstream and Chemical businesses reduce the Corporation’s enterprise-wide risk from changes in commodity prices, currency rates and interest rates. In addition, the Corporation uses commodity-based contracts, including derivatives, to manage commodity price risk and for trading purposes. Commodity contracts held for trading purposes are presented in the Consolidated Statement of Income on a net basis in the line “Sales and other operating revenue”. The Corporation’s commodity derivatives are not accounted for under hedge accounting. At times, the Corporation also enters into currency and interest rate derivatives, none of which are material to the Corporation’s financial position as of December 31, 2020 and 2019, or results of operations for the years ended 2020, 2019 and 2018.

Credit risk associated with the Corporation’s derivative position is mitigated by several factors, including the use of derivative clearing exchanges and the quality of and financial limits placed on derivative counterparties. The Corporation maintains a system of controls that includes the authorization, reporting and monitoring of derivative activity.

The net notional long/(short) position of derivative instruments at December 31, 2020, and December 31, 2019, was as follows:


	December 31,	December 31,
	2020	2019
	(millions)
Crude oil (barrels)	40	57
Petroleum products (barrels)	(46)	(38)
Natural gas (MMBTUs)	(500)	(165)

Realized and unrealized gains/(losses) on derivative instruments that were recognized in the Consolidated Statement of Income are included in the following lines on a before-tax basis:


	2020	2019	2018
	(millions of dollars)
Sales and other operating revenue	404	(412)	130
Crude oil and product purchases	(407)	179	(120)
Total	(3)	(233)	10

Long-Term Debt

12 Months Ended

Dec. 31, 2020

Long-term Debt, Unclassified [Abstract]

Long-Term Debt

At December 31, 2020, long-term debt consisted of $41,026 million due in U.S. dollars and $6,156 million representing the U.S. dollar equivalent at year-end exchange rates of amounts payable in foreign currencies. These amounts exclude that portion of long-term debt, totaling $2,930 million, which matures within one year and is included in current liabilities. The increase in the estimated fair value and book value of long-term debt reflects the Corporation’s issuance of $23 billion of long-term debt during 2020. The amounts of long-term debt, excluding finance lease obligations, maturing in each of the four years after December 31, 2021, in millions of dollars, are: 2022 – $3,340; 2023 – $4,024; 2024 – $3,968; and 2025 – $4,672. At December 31, 2020, the Corporation had no unused long-term lines of credit.

The Corporation may use non-derivative financial instruments, such as its foreign currency-denominated debt, as hedges of its net investments in certain foreign subsidiaries. Under this method, the change in the carrying value of the financial instruments due to foreign exchange fluctuations is reported in accumulated other comprehensive income. As of December 31, 2020, the Corporation has designated its $5.5 billion of Euro-denominated long-term debt and related accrued interest as a net investment hedge of its European business. The net investment hedge is deemed to be perfectly effective.

Summarized long-term debt at year-end 2020 and 2019 are shown in the table below:


	Average Rate (1)	Dec 31, 2020	Dec 31, 2019
		(millions of dollars)
Exxon Mobil Corporation (2)
2.222% notes due 2021		—	2,500
2.397% notes due 2022		1,150	1,150
1.902% notes due 2022		750	750
Floating-rate notes due 2022 (Issued 2015)	1.118%	500	500
Floating-rate notes due 2022 (Issued 2019)	1.189%	750	750
1.571% notes due 2023		2,750	—
2.726% notes due 2023		1,250	1,250
3.176% notes due 2024		1,000	1,000
2.019% notes due 2024		1,000	1,000
2.709% notes due 2025		1,750	1,750
2.992% notes due 2025		2,807	—
3.043% notes due 2026		2,500	2,500
2.275% notes due 2026		1,000	1,000
3.294% notes due 2027		1,000	—
2.440% notes due 2029		1,250	1,250
3.482% notes due 2030		2,000	—
2.610% notes due 2030		2,000	—
2.995% notes due 2039		750	750
4.227% notes due 2040		2,091	—
3.567% notes due 2045		1,000	1,000
4.114% notes due 2046		2,500	2,500
3.095% notes due 2049		1,500	1,500
4.327% notes due 2050		2,750	—
3.452% notes due 2051		2,750	—
Exxon Mobil Corporation - Euro-denominated
0.142% notes due 2024		1,841	—
0.524% notes due 2028		1,227	—
0.835% notes due 2032		1,227	—
1.408% notes due 2039		1,227	—
XTO Energy Inc. (3)
6.100% senior notes due 2036		192	193
6.750% senior notes due 2037		294	296
6.375% senior notes due 2038		227	229
Mobil Corporation
8.625% debentures due 2021		—	250

Industrial revenue bonds due 2022-2051	0.437%	2,461	2,461
Other U.S. dollar obligations		78	89
Other foreign currency obligations		61	64
Finance lease obligations	8.730%	1,680	1,670
Debt issuance costs		(131)	(60)
Total long-term debt		47,182	26,342

(1)Average effective interest rate for debt and average imputed interest rate for finance leases at December 31, 2020.

(2)Includes premiums of $148 million in 2020.

(3)Includes premiums of $87 million in 2020 and $92 million in 2019.

Incentive Program

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Incentive Program

The 2003 Incentive Program provides for grants of stock options, stock appreciation rights (SARs), restricted stock, and other forms of awards. Awards may be granted to eligible employees of the Corporation and those affiliates at least 50 percent owned. Outstanding awards are subject to certain forfeiture provisions contained in the program or award instrument. Options and SARs may be granted at prices not less than 100 percent of market value on the date of grant and have a maximum life of 10 years. The maximum number of shares of stock that may be issued under the 2003 Incentive Program is 220 million. Awards that are forfeited, expire, or are settled in cash, do not count against this maximum limit. The 2003 Incentive Program does not have a specified term. New awards may be made until the available shares are depleted, unless the Board terminates the plan early. At the end of 2020, remaining shares available for award under the 2003 Incentive Program were 71 million.

Restricted Stock and Restricted Stock Units. Awards totaling 8,681 thousand, 8,936 thousand, and 8,771 thousand of restricted (nonvested) common stock units were granted in 2020, 2019, and 2018, respectively. Compensation expense for these awards is based on the price of the stock at the date of grant and is recognized in income over the requisite service period. Shares for these awards are issued to employees from treasury stock. The units that are settled in cash are recorded as liabilities and their changes in fair value are recognized over the vesting period. During the applicable restricted periods, the shares and units may not be sold or transferred and are subject to forfeiture. The majority of the awards have graded vesting periods, with 50 percent of the shares and units in each award vesting after three years and the remaining 50 percent vesting after seven years. Awards granted to a small number of senior executives have vesting periods of five years for 50 percent of the award and of 10 years for the remaining 50 percent of the award, except that for awards granted prior to 2020 the vesting of the 10-year portion of the award is delayed until retirement if later than 10 years.

The Corporation has purchased shares in the open market and through negotiated transactions to offset shares or units settled in shares issued in conjunction with benefit plans and programs. The Corporation suspended its first quarter 2021 anti-dilutive share repurchase program due to current market uncertainty and intends to resume this program in the future as market conditions improve.

The following tables summarize information about restricted stock and restricted stock units for the year ended December 31, 2020.


	2020
Restricted stock and units outstanding	Shares	Weighted Average Grant-Date Fair Value per Share
	(thousands)	(dollars)
Issued and outstanding at January 1	39,628	84.50
Awards issued in 2020	9,030	68.95
Vested	(8,990)	86.84
Forfeited	(83)	82.04
Issued and outstanding at December 31	39,585	80.43


Value of restricted stock units	2020	2019	2018
Grant price (dollars)	41.15	68.77	77.66

Value at date of grant:	(millions of dollars)
Units settled in stock	325	559	620
Units settled in cash	32	55	61
Total value	357	614	681

As of December 31, 2020, there was $1,356 million of unrecognized compensation cost related to the nonvested restricted awards. This cost is expected to be recognized over a weighted-average period of 4.2 years. The compensation cost charged against income for the restricted stock and restricted stock units was $672 million, $741 million, and $774 million for 2020, 2019, and 2018, respectively. The income tax benefit recognized in income related to this compensation expense was $51 million, $51 million, and $42 million for the same periods, respectively. The fair value of shares and units vested in 2020, 2019, and 2018 was $367 million, $647 million, and $722 million, respectively. Cash payments of $34 million, $56 million, and $61 million for vested restricted stock units settled in cash were made in 2020, 2019, and 2018, respectively.

Litigation And Other Contingencies

12 Months Ended

Dec. 31, 2020

Loss Contingency [Abstract]

Litigation And Other Contingencies

Litigation and Other Contingencies

Litigation. A variety of claims have been made against ExxonMobil and certain of its consolidated subsidiaries in a number of pending lawsuits. Management has regular litigation reviews, including updates from corporate and outside counsel, to assess the need for accounting recognition or disclosure of these contingencies. The Corporation accrues an undiscounted liability for those contingencies where the incurrence of a loss is probable and the amount can be reasonably estimated. If a range of amounts can be reasonably estimated and no amount within the range is a better estimate than any other amount, then the minimum of the range is accrued. The Corporation does not record liabilities when the likelihood that the liability has been incurred is probable but the amount cannot be reasonably estimated or when the liability is believed to be only reasonably possible or remote. For contingencies where an unfavorable outcome is reasonably possible and which are significant, the Corporation discloses the nature of the contingency and, where feasible, an estimate of the possible loss. For purposes of our contingency disclosures, “significant” includes material matters, as well as other matters, which management believes should be disclosed. ExxonMobil will continue to defend itself vigorously in these matters. Based on a consideration of all relevant facts and circumstances, the Corporation does not believe the ultimate outcome of any currently pending lawsuit against ExxonMobil will have a material adverse effect upon the Corporation’s operations, financial condition, or financial statements taken as a whole.

Other Contingencies. The Corporation and certain of its consolidated subsidiaries were contingently liable at December 31, 2020, for guarantees relating to notes, loans and performance under contracts. Where guarantees for environmental remediation and other similar matters do not include a stated cap, the amounts reflect management’s estimate of the maximum potential exposure.


	December 31, 2020
	Equity Company Obligations (1)	Other Third-Party Obligations	Total
	(millions of dollars)
Guarantees
Debt-related	986	124	1,110
Other	745	4,944	5,689
Total	1,731	5,068	6,799

(1)ExxonMobil share.

Additionally, the Corporation and its affiliates have numerous long-term sales and purchase commitments in their various business activities, all of which are expected to be fulfilled with no adverse consequences material to the Corporation’s operations or financial condition.

In accordance with a Venezuelan nationalization decree issued in February 2007, a subsidiary of the Venezuelan National Oil Company (PdVSA) assumed the operatorship of the Cerro Negro Heavy Oil Project. The decree also required conversion of the Cerro Negro Project into a “mixed enterprise” and an increase in PdVSA’s or one of its affiliate’s ownership interest in the Project. ExxonMobil refused to accede to the terms proffered by the government, and on June 27, 2007, the government expropriated ExxonMobil’s 41.67 percent interest in the Cerro Negro Project.

ExxonMobil collected awards of $908 million in an arbitration against PdVSA under the rules of the International Chamber of Commerce in respect of an indemnity related to the Cerro Negro Project and $260 million in an arbitration for compensation due for the La Ceiba Project and for export curtailments at the Cerro Negro Project under rules of International Centre for Settlement of Investment Disputes (ICSID). An ICSID arbitration award relating to the Cerro Negro Project’s expropriation ($1.4 billion) was annulled based on a determination that a prior Tribunal failed to adequately explain why the cap on damages in the indemnity owed by PdVSA did not affect or limit the amount owed for the expropriation of the Cerro Negro Project. ExxonMobil filed a new claim seeking to restore the original award of damages for the Cerro Negro Project with ICSID on September 26, 2018.

The net impact of this matter on the Corporation’s consolidated financial results cannot be reasonably estimated. Regardless, the Corporation does not expect the resolution to have a material effect upon the Corporation’s operations or financial condition.

An affiliate of ExxonMobil is one of the Contractors under a Production Sharing Contract (PSC) with the Nigerian National Petroleum Corporation (NNPC) covering the Erha block located in the offshore waters of Nigeria. ExxonMobil's affiliate is the operator of the block and owns a 56.25 percent interest under the PSC. The Contractors are in dispute with NNPC regarding NNPC's lifting of crude oil in excess of its entitlement under the terms of the PSC. In accordance with the terms of the PSC, the Contractors initiated arbitration in Abuja, Nigeria, under the Nigerian Arbitration and Conciliation Act. On October 24, 2011, a three-member arbitral Tribunal issued an award upholding the Contractors' position in all material respects and awarding damages to the Contractors jointly in an amount of approximately $1.8 billion plus $234 million in accrued interest. The Contractors petitioned a Nigerian federal court for enforcement of the award, and NNPC petitioned the same court to have the award set aside. On May 22, 2012, the court set aside the award. The Contractors appealed that judgment to the Court of Appeal, Abuja Judicial Division. On July 22, 2016, the Court of Appeal upheld the decision of the lower court setting aside the award. On October 21, 2016, the Contractors appealed the decision to the Supreme Court of Nigeria. In June 2013, the Contractors filed a lawsuit against NNPC in the Nigerian federal high court in order to preserve their ability to seek enforcement of the PSC in the courts if necessary. Following dismissal by this court, the Contractors appealed to the Nigerian Court of Appeal in June 2016. In October 2014, the Contractors filed suit in the United States District Court for the Southern District of New York (SDNY) to enforce, if necessary, the arbitration award against NNPC assets residing within that jurisdiction. NNPC moved to dismiss the lawsuit. On September 4, 2019, the SDNY dismissed the Contractors’ petition to recognize and enforce the Erha arbitration award. The Contractors filed a notice of appeal in the Second Circuit on October 2, 2019. At this time, the net impact of this matter on the Corporation's consolidated financial results cannot be reasonably estimated. However, regardless of the outcome of enforcement proceedings, the Corporation does not expect the proceedings to have a material effect upon the Corporation's operations or financial condition.

Pension And Other Postretirement Benefits

12 Months Ended

Dec. 31, 2020

Retirement Benefits [Abstract]

Pension And Other Postretirement Benefits

Pension and Other Postretirement Benefits

The benefit obligations and plan assets associated with the Corporation’s principal benefit plans are measured on December 31.


	Pension Benefits				Other Postretirement
	U.S.		Non-U.S.		Benefits
	2020	2019	2020	2019	2020	2019
	(percent)
Weighted-average assumptions used to determine benefit obligations at December 31
Discount rate	2.80	3.50	1.60	2.30	2.80	3.50
Long-term rate of compensation increase	5.50	5.75	4.20	4.80	5.50	5.75

	(millions of dollars)
Change in benefit obligation
Benefit obligation at January 1	20,959	18,174	29,918	25,378	8,113	7,471
Service cost	965	757	707	551	181	139
Interest cost	708	766	657	763	277	315
Actuarial loss/(gain) (1)	1,287	2,562	2,344	3,703	(66)	556
Benefits paid (2) (3)	(1,987)	(1,300)	(1,317)	(1,196)	(510)	(517)
Foreign exchange rate changes	—	—	1,375	391	23	25
Amendments, divestments and other	(270)	—	(58)	328	117	124
Benefit obligation at December 31	21,662	20,959	33,626	29,918	8,135	8,113
Accumulated benefit obligation at December 31	17,502	16,387	30,952	27,236	—	—

(1)Actuarial loss/(gain) primarily reflects changes in discount rates, partially offset by lower long-term rates of compensation.

(2)Benefit payments for funded and unfunded plans.

(3)For 2020 and 2019, other postretirement benefits paid are net of $16 million and $20 million of Medicare subsidy receipts, respectively.

For selection of the discount rate for U.S. plans, several sources of information are considered, including interest rate market indicators and the effective discount rate determined by use of a yield curve based on high-quality, noncallable bonds applied to the estimated cash outflows for benefit payments. For major non-U.S. plans, the discount rate is determined by using a spot yield curve of high-quality, local-currency-denominated bonds at an average maturity approximating that of the liabilities.

The measurement of the accumulated postretirement benefit obligation assumes a health care cost trend rate of 4.5 percent in 2022 and subsequent years.


	Pension Benefits				Other Postretirement
	U.S.		Non-U.S.		Benefits
	2020	2019	2020	2019	2020	2019
	(millions of dollars)
Change in plan assets
Fair value at January 1	13,636	11,134	22,916	19,486	425	386
Actual return on plan assets	2,269	2,521	2,795	3,210	42	54
Foreign exchange rate changes	—	—	1,011	513	—	—
Company contribution	1,004	1,022	597	602	37	41
Benefits paid (1)	(1,609)	(1,041)	(992)	(883)	(58)	(56)
Other	—	—	(111)	(12)	—	—
Fair value at December 31	15,300	13,636	26,216	22,916	446	425

(1) Benefit payments for funded plans.

The funding levels of all qualified pension plans are in compliance with standards set by applicable law or regulation. As shown in the table below, certain smaller U.S. pension plans and a number of non-U.S. pension plans are not funded because local applicable tax rules and regulatory practices do not encourage funding of these plans. All defined benefit pension obligations, regardless of the funding status of the underlying plans, are fully supported by the financial strength of the Corporation or the respective sponsoring affiliate.


	Pension Benefits
	U.S.		Non-U.S.
	2020	2019	2020	2019
	(millions of dollars)
Assets in excess of/(less than) benefit obligation
Balance at December 31
Funded plans	(4,156)	(4,656)	(1,223)	(1,728)
Unfunded plans	(2,206)	(2,667)	(6,187)	(5,274)
Total	(6,362)	(7,323)	(7,410)	(7,002)

The authoritative guidance for defined benefit pension and other postretirement plans requires an employer to recognize the overfunded or underfunded status of a defined benefit postretirement plan as an asset or liability in its statement of financial position and to recognize changes in that funded status in the year in which the changes occur through other comprehensive income.


	Pension Benefits				Other Postretirement Benefits
	U.S.		Non-U.S.
	2020	2019	2020	2019	2020	2019
	(millions of dollars)
Assets in excess of/(less than) benefit obligation
Balance at December 31 (1)	(6,362)	(7,323)	(7,410)	(7,002)	(7,689)	(7,688)

Amounts recorded in the consolidated balance sheet consist of:
Other assets	—	—	1,931	1,151	—	—
Current liabilities	(377)	(242)	(273)	(267)	(327)	(351)
Postretirement benefits reserves	(5,985)	(7,081)	(9,068)	(7,886)	(7,362)	(7,337)
Total recorded	(6,362)	(7,323)	(7,410)	(7,002)	(7,689)	(7,688)

Amounts recorded in accumulated other comprehensive income consist of:
Net actuarial loss/(gain)	3,102	3,971	5,904	5,662	1,164	1,339
Prior service cost	(275)	1	208	360	(274)	(315)
Total recorded in accumulated other comprehensive income	2,827	3,972	6,112	6,022	890	1,024

(1) Fair value of assets less benefit obligation shown on the preceding page.

The long-term expected rate of return on funded assets shown below is established for each benefit plan by developing a forward-looking, long-term return assumption for each asset class, taking into account factors such as the expected real return for the specific asset class and inflation. A single, long-term rate of return is then calculated as the weighted average of the target asset allocation percentages and the long-term return assumption for each asset class.


	Pension Benefits						Other Postretirement Benefits
	U.S.			Non-U.S.
	2020	2019	2018	2020	2019	2018	2020	2019	2018
Weighted-average assumptions used to determine net periodic benefit cost for years ended December 31	(percent)
Discount rate	3.50	4.40	3.80	2.30	3.00	2.80	3.50	4.40	3.80
Long-term rate of return on funded assets	5.30	5.30	6.00	4.10	4.10	4.70	4.60	4.60	6.00
Long-term rate of compensation increase	5.75	5.75	5.75	4.80	4.30	4.30	5.75	5.75	5.75

Components of net periodic benefit cost	(millions of dollars)
Service cost	965	757	819	707	551	608	181	139	152
Interest cost	708	766	721	657	763	754	277	315	301
Expected return on plan assets	(703)	(568)	(727)	(897)	(777)	(951)	(18)	(15)	(23)
Amortization of actuarial loss/(gain)	310	305	362	416	306	409	95	55	116
Amortization of prior service cost	5	5	5	68	56	46	(42)	(42)	(40)
Net pension enhancement and curtailment/settlement cost	280	164	268	49	(98)	44	—	—	—
Net periodic benefit cost	1,565	1,429	1,448	1,000	801	910	493	452	506

Changes in amounts recorded in accumulated other comprehensive income:
Net actuarial loss/(gain)	(279)	609	479	446	1,268	(66)	(92)	517	(594)
Amortization of actuarial (loss)/gain	(590)	(469)	(630)	(442)	(208)	(453)	(95)	(55)	(116)
Prior service cost/(credit)	(271)	—	—	(82)	379	98	—	—	—
Amortization of prior service (cost)/credit	(5)	(5)	(5)	(68)	(56)	(46)	42	42	40
Foreign exchange rate changes	—	—	—	236	19	(356)	11	—	(8)
Total recorded in other comprehensive income	(1,145)	135	(156)	90	1,402	(823)	(134)	504	(678)
Total recorded in net periodic benefit cost and other comprehensive income, before tax	420	1,564	1,292	1,090	2,203	87	359	956	(172)

Costs for defined contribution plans were $358 million, $422 million and $391 million in 2020, 2019 and 2018, respectively.

A summary of the change in accumulated other comprehensive income is shown in the table below:


	Total Pension and Other Postretirement Benefits
	2020	2019	2018
	(millions of dollars)
(Charge)/credit to other comprehensive income, before tax
U.S. pension	1,145	(135)	156
Non-U.S. pension	(90)	(1,402)	823
Other postretirement benefits	134	(504)	678
Total (charge)/credit to other comprehensive income, before tax	1,189	(2,041)	1,657
(Charge)/credit to income tax (see Note 4)	(153)	550	(470)
(Charge)/credit to investment in equity companies	(110)	(19)	24
(Charge)/credit to other comprehensive income including noncontrolling interests, after tax	926	(1,510)	1,211
Charge/(credit) to equity of noncontrolling interests	30	146	(114)
(Charge)/credit to other comprehensive income attributable to ExxonMobil	956	(1,364)	1,097

The Corporation’s investment strategy for benefit plan assets reflects a long-term view, a careful assessment of the risks inherent in plan assets and liabilities and broad diversification to reduce the risk of the portfolio. The benefit plan assets are primarily invested in passive global equity and local currency fixed income index funds to diversify risk while minimizing costs. The equity funds hold ExxonMobil stock only to the extent necessary to replicate the relevant equity index. The fixed income funds are largely invested in investment grade corporate and government debt securities.

Studies are periodically conducted to establish the preferred target asset allocation percentages. The target asset allocation for the U.S. benefit plans and the major non-U.S. plans is 30 percent equity securities and 70 percent debt securities. The equity for the U.S. and certain non-U.S. plans include a small allocation to private equity partnerships that primarily focus on early-stage venture capital of 4 percent and 2 percent, respectively.

The fair value measurement levels are accounting terms that refer to different methods of valuing assets. The terms do not represent the relative risk or credit quality of an investment.

The 2020 fair value of the benefit plan assets, including the level within the fair value hierarchy, is shown in the tables below:


	U.S. Pension						Non- U.S. Pension
	Fair Value Measurement at December 31, 2020, Using:						Fair Value Measurement at December 31, 2020, Using:
	Level 1	Level 2		Level 3	Net Asset Value	Total	Level 1		Level 2		Level 3	Net Asset Value	Total
	(millions of dollars)
Asset category:
Equity securities
U.S.	—	—		—	2,323	2,323	—		—		—	4,177	4,177
Non-U.S.	—	—		—	1,703	1,703	89	(1)	—		—	3,285	3,374
Private equity	—	—		—	548	548	—		—		—	530	530
Debt securities
Corporate	—	5,146	(2)	—	1	5,147	—		138	(2)	—	5,212	5,350
Government	—	5,261	(2)	—	2	5,263	250	(3)	116	(2)	—	11,993	12,359
Asset-backed	—	—		—	1	1	—		24	(2)	—	239	263
Cash	—	—		—	308	308	69		21	(4)	—	50	140
Total at fair value	—	10,407		—	4,886	15,293	408		299		—	25,486	26,193
Insurance contracts at contract value						7							23
Total plan assets						15,300							26,216

(1)For non-U.S. equity securities held in separate accounts, fair value is based on observable quoted prices on active exchanges.

(2)For corporate, government and asset-backed debt securities, fair value is based on observable inputs of comparable market transactions.

(3)For government debt securities that are traded on active exchanges, fair value is based on observable quoted prices.

(4)For cash balances that are subject to withdrawal penalties or other adjustments, the fair value is treated as a Level 2 input.


	Other Postretirement
	Fair Value Measurement at December 31, 2020, Using:
	Level 1		Level 2		Level 3	Net Asset Value	Total
	(millions of dollars)
Asset category:
Equity securities
U.S.	88	(1)	—		—	—	88
Non-U.S.	48	(1)	—		—	—	48
Debt securities
Corporate	—		103	(2)	—	—	103
Government	—		204	(2)	—	—	204
Asset-backed	—		—		—	—	—
Cash	—		—		—	3	3
Total at fair value	136		307		—	3	446

(1)For equity securities held in separate accounts, fair value is based on observable quoted prices on active exchanges.

(2)For corporate, government and asset-backed debt securities, fair value is based on observable inputs of comparable market transactions.

The 2019 fair value of the benefit plan assets, including the level within the fair value hierarchy, is shown in the tables below:


	U.S. Pension						Non-U.S. Pension
	Fair Value Measurement at December 31, 2019, Using:						Fair Value Measurement at December 31, 2019, Using:
	Level 1	Level 2		Level 3	Net Asset Value	Total		Level 1		Level 2		Level 3	Net Asset Value	Total
	(millions of dollars)
Asset category:
Equity securities
U.S.	—	—		—	1,960	1,960		—		—		—	3,436	3,436
Non-U.S.	—	—		—	1,656	1,656		70	(1)	—		—	3,015	3,085
Private equity	—	—		—	499	499		—		—		—	489	489
Debt securities
Corporate	—	4,932	(2)	—	1	4,933		—		129	(2)	—	4,486	4,615
Government	—	4,470	(2)	—	2	4,472		280	(3)	139	(2)	—	10,511	10,930
Asset-backed	—	—		—	1	1		—		21	(2)	—	212	233
Cash	—	—		—	107	107		33		12	(4)	—	61	106
Total at fair value	—	9,402		—	4,226	13,628		383		301		—	22,210	22,894
Insurance contracts at contract value						8								22
Total plan assets						13,636								22,916

(1)For non-U.S. equity securities held in separate accounts, fair value is based on observable quoted prices on active exchanges.

(2)For corporate, government and asset-backed debt securities, fair value is based on observable inputs of comparable market transactions.

(3)For government debt securities that are traded on active exchanges, fair value is based on observable quoted prices.

(4)For cash balances that are subject to withdrawal penalties or other adjustments, the fair value is treated as a Level 2 input.


	Other Postretirement
	Fair Value Measurement at December 31, 2019, Using:
	Level 1	Level 2		Level 3	Net Asset Value	Total
	(millions of dollars)
Asset category:
Equity securities
U.S.	—	—		—	81	81
Non-U.S.	—	—		—	49	49
Debt securities
Corporate	—	92	(1)	—	—	92
Government	—	200	(1)	—	—	200
Asset-backed	—	—		—	—	—
Cash	—	—		—	3	3
Total at fair value	—	292		—	133	425

(1)For corporate, government and asset-backed debt securities, fair value is based on observable inputs of comparable market transactions.

A summary of pension plans with an accumulated benefit obligation and projected benefit obligation in excess of plan assets is shown in the table below:


	Pension Benefits
	U.S.		Non-U.S.
	2020	2019	2020	2019
	(millions of dollars)
For funded pension plans with an accumulated benefit obligation
in excess of plan assets:
Accumulated benefit obligation	16,129	14,940	4,602	3,026
Fair value of plan assets	15,300	13,636	2,652	1,381

For funded pension plans with a projected benefit obligation in excess of plan assets:
Projected benefit obligation	19,456	18,292	13,836	12,496
Fair value of plan assets	15,300	13,636	10,681	9,616

For unfunded pension plans:
Projected benefit obligation	2,206	2,667	6,187	5,274
Accumulated benefit obligation	1,373	1,447	5,469	4,629

All other postretirement benefit plans are unfunded or underfunded.


	Pension Benefits		Other Postretirement Benefits
	U.S.	Non-U.S.	Gross	Medicare Subsidy Receipt
	(millions of dollars)
Contributions expected in 2021	865	395	—	—
Benefit payments expected in:
2021	2,434	1,310	424	22
2022	1,079	1,193	426	23
2023	1,105	1,214	420	25
2024	1,124	1,240	418	26
2025	1,142	1,186	415	27
2026 - 2030	5,971	6,274	2,058	143

Disclosures About Segments And Related Information

12 Months Ended

Dec. 31, 2020

Segment Reporting, Measurement Disclosures [Abstract]

Disclosures About Segments And Related Information

Disclosures about Segments and Related Information

The Upstream, Downstream and Chemical functions best define the operating segments of the business that are reported separately. The factors used to identify these reportable segments are based on the nature of the operations that are undertaken by each segment. The Upstream segment is organized and operates to explore for and produce crude oil and natural gas. The Downstream segment is organized and operates to manufacture and sell petroleum products. The Chemical segment is organized and operates to manufacture and sell petrochemicals. These segments are broadly understood across the petroleum and petrochemical industries.

These functions have been defined as the operating segments of the Corporation because they are the segments (1) that engage in business activities from which revenues are recognized and expenses are incurred; (2) whose operating results are regularly reviewed by the Corporation’s chief operating decision maker to make decisions about resources to be allocated to the segment and to assess its performance; and (3) for which discrete financial information is available.

Earnings after income tax include transfers at estimated market prices.

In the Corporate and financing segment, interest revenue relates to interest earned on cash deposits and marketable securities. Interest expense includes non-debt-related interest expense of $148 million in 2020, $105 million in 2019 and $84 million in 2018.


	Upstream		Downstream		Chemical		Corporate and	Corporate
	U.S.	Non-U.S.	U.S.	Non-U.S.	U.S.	Non-U.S.	Financing	Total
	(millions of dollars)
As of December 31, 2020
Earnings (Loss) after income tax	(19,385)	(645)	(852)	(225)	1,277	686	(3,296)	(22,440)
Effect of asset impairments - noncash	(17,138)	(2,287)	(15)	(609)	(100)	(69)	(35)	(20,253)
Earnings of equity companies included above	(559)	2,101	134	(190)	(21)	651	(384)	1,732
Sales and other operating revenue	5,876	8,673	48,256	92,640	8,529	14,562	38	178,574
Intersegment revenue	8,508	19,642	12,258	15,162	6,099	3,881	221	—
Depreciation and depletion expense	28,627	12,723	716	1,672	685	694	892	46,009
Interest revenue	—	—	—	—	—	—	49	49
Interest expense	52	93	1	21	—	—	991	1,158
Income tax expense (benefit)	(5,958)	742	(324)	393	440	272	(1,197)	(5,632)
Additions to property, plant and equipment	5,726	4,418	2,983	1,731	1,221	592	671	17,342
Investments in equity companies	4,792	18,135	352	879	2,543	3,514	(443)	29,772
Total assets	71,287	144,730	23,754	34,848	17,839	20,220	20,072	332,750

As of December 31, 2019
Earnings after income tax	536	13,906	1,717	606	206	386	(3,017)	14,340
Earnings of equity companies included above	282	4,534	196	19	(4)	818	(404)	5,441
Sales and other operating revenue	9,364	13,779	70,523	134,460	9,723	17,693	41	255,583
Intersegment revenue	10,893	30,864	22,416	24,775	7,864	5,905	224	—
Depreciation and depletion expense	6,162	9,305	674	832	555	621	849	18,998
Interest revenue	—	—	—	—	—	—	84	84
Interest expense	54	34	1	9	—	1	731	830
Income tax expense (benefit)	(151)	5,509	465	361	58	305	(1,265)	5,282
Additions to property, plant and equipment	10,404	7,347	2,685	1,777	1,344	589	758	24,904
Investments in equity companies	5,313	17,736	319	1,062	1,835	3,335	(309)	29,291
Total assets	95,750	151,181	23,442	37,133	16,544	20,376	18,171	362,597

As of December 31, 2018
Earnings after income tax	1,739	12,340	2,962	3,048	1,642	1,709	(2,600)	20,840
Earnings of equity companies included above	608	5,816	156	(6)	48	1,113	(380)	7,355
Sales and other operating revenue	10,359	15,158	74,327	147,007	12,239	20,204	38	279,332
Intersegment revenue	8,683	29,659	21,954	29,888	9,044	7,217	205	—
Depreciation and depletion expense	6,024	9,257	684	890	405	606	879	18,745
Interest revenue	—	—	—	—	—	—	64	64
Interest expense	77	31	2	12	—	1	643	766
Income tax expense (benefit)	104	8,149	946	1,008	566	245	(1,486)	9,532
Additions to property, plant and equipment	7,119	7,974	1,152	1,595	1,146	348	717	20,051
Investments in equity companies	4,566	16,337	293	1,162	870	3,431	(277)	26,382
Total assets	90,310	148,914	17,898	34,024	14,904	21,131	19,015	346,196

Geographic


Sales and other operating revenue	2020	2019	2018
	(millions of dollars)
United States	62,663	89,612	96,930
Non-U.S.	115,911	165,971	182,402
Total	178,574	255,583	279,332

Significant non-U.S. revenue sources include: (1)
Canada	13,093	19,735	22,672
United Kingdom	11,055	17,479	18,702
Singapore	9,442	12,128	13,689
France	8,676	12,740	13,637
Italy	7,091	10,459	13,396
Belgium	6,231	11,644	15,664
Australia	5,839	7,941	8,780

(1)Revenue is determined by primary country of operations. Excludes certain sales and other operating revenues in Non-U.S. operations where attribution to a specific country is not practicable.


	December 31,
Long-lived assets	2020	2019	2018
	(millions of dollars)
United States	94,732	114,372	108,147
Non-U.S.	132,821	138,646	138,954
Total	227,553	253,018	247,101

Significant non-U.S. long-lived assets include:
Canada	36,232	39,130	37,433
Australia	14,792	13,933	14,548
Singapore	12,129	11,645	11,148
Kazakhstan	8,882	9,315	9,726
Papua New Guinea	7,803	8,057	8,269
Nigeria	6,345	7,640	8,421
United Arab Emirates	5,381	5,262	4,859
Russia	4,616	5,135	5,456
Angola	4,405	5,784	7,021

Income And Other Taxes

12 Months Ended

Dec. 31, 2020

Income And Other Taxes [Abstract]

Income And Other Taxes

Income and Other Taxes


	2020			2019			2018
	U.S.	Non-U.S.	Total	U.S.	Non-U.S.	Total	U.S.	Non-U.S.	Total
				(millions of dollars)
Income tax expense (benefit)
Federal and non-U.S.
Current	262	2,908	3,170	(121)	6,171	6,050	459	9,001	9,460
Deferred - net	(6,045)	(2,007)	(8,052)	(255)	(420)	(675)	518	(614)	(96)
U.S. tax on non-U.S. operations	13	—	13	89	—	89	42	—	42
Total federal and non-U.S.	(5,770)	901	(4,869)	(287)	5,751	5,464	1,019	8,387	9,406
State	(763)	—	(763)	(182)	—	(182)	126	—	126
Total income tax expense (benefit)	(6,533)	901	(5,632)	(469)	5,751	5,282	1,145	8,387	9,532
All other taxes and duties
Other taxes and duties	3,108	23,014	26,122	3,566	26,959	30,525	3,498	29,165	32,663
Included in production and manufacturing expenses	1,148	663	1,811	1,385	811	2,196	1,245	857	2,102
Included in SG&A expenses	164	328	492	160	305	465	153	312	465
Total other taxes and duties	4,420	24,005	28,425	5,111	28,075	33,186	4,896	30,334	35,230
Total	(2,113)	24,906	22,793	4,642	33,826	38,468	6,041	38,721	44,762

The above provisions for deferred income taxes include net benefits of $25 million in 2020, $740 million in 2019, and $289 million in 2018 related to changes in tax laws and rates, and a benefit of $6.3 billion in 2020 related to asset impairments.

The reconciliation between income tax expense (credit) and a theoretical U.S. tax computed by applying a rate of 21 percent for 2020, 2019 and 2018 is as follows:


	2020		2019		2018
	(millions of dollars)
Income (Loss) before income taxes
United States	(27,704)		(53)		5,200
Non-U.S.	(1,179)		20,109		25,753
Total	(28,883)		20,056		30,953
Theoretical tax	(6,065)		4,212		6,500
Effect of equity method of accounting	(364)		(1,143)		(1,545)
Non-U.S. taxes in excess of/(less than) theoretical U.S. tax (1)(2)	1,606		2,573		4,626
State taxes, net of federal tax benefit (1)	(603)		(144)		100
Enactment-date effects of U.S. tax reform	—		—		(291)
Other	(206)		(216)		142
Total income tax expense (credit)	(5,632)		5,282		9,532

Effective tax rate calculation
Income tax expense (credit)	(5,632)		5,282		9,532
ExxonMobil share of equity company income taxes	861		2,490		3,142
Total income tax expense (credit)	(4,771)		7,772		12,674
Net income (loss) including noncontrolling interests	(23,251)		14,774		21,421
Total income (loss) before taxes	(28,022)		22,546		34,095
Effective income tax rate	17	%	34	%	37	%

(1)2020 includes the impact of an increase in valuation allowance of $647 million in non-U.S. and $115 million in U.S. state jurisdictions.

(2)2019 includes taxes less than the theoretical U.S. tax of $773 million from Norway operations and the sale of upstream assets, $657 million from a tax rate change in Alberta, Canada, and $268 million from an adjustment to a prior year tax position.

Deferred income taxes reflect the impact of temporary differences between the amount of assets and liabilities recognized for financial reporting purposes and such amounts recognized for tax purposes.

Deferred tax liabilities/(assets) are comprised of the following at December 31:


Tax effects of temporary differences for:	2020	2019
	(millions of dollars)
Property, plant and equipment	28,778	36,029
Other liabilities	6,427	7,653
Total deferred tax liabilities	35,205	43,682

Pension and other postretirement benefits	(4,703)	(4,712)
Asset retirement obligations	(3,150)	(3,403)
Tax loss carryforwards	(8,982)	(7,404)
Other assets	(7,095)	(7,735)
Total deferred tax assets	(23,930)	(23,254)

Asset valuation allowances	2,731	1,924
Net deferred tax liabilities	14,006	22,352

In 2020, asset valuation allowances of $2,731 million increased by $807 million and included net provisions of $762 million and foreign currency effects of $41 million.


Balance sheet classification	2020	2019
	(millions of dollars)
Other assets, including intangibles, net	(4,159)	(3,268)
Deferred income tax liabilities	18,165	25,620
Net deferred tax liabilities	14,006	22,352

The Corporation’s undistributed earnings from subsidiary companies outside the United States include amounts that have been retained to fund prior and future capital project expenditures. Deferred income taxes have not been recorded for potential future tax obligations, such as foreign withholding tax and state tax, as these undistributed earnings are expected to be indefinitely reinvested for the foreseeable future. As of December 31, 2020, it is not practicable to estimate the unrecognized deferred tax liability. However, unrecognized deferred taxes on remittance of these funds are not expected to be material.

Unrecognized Tax Benefits. The Corporation is subject to income taxation in many jurisdictions around the world. Unrecognized tax benefits reflect the difference between positions taken or expected to be taken on income tax returns and the amounts recognized in the financial statements. The following table summarizes the movement in unrecognized tax benefits:


Gross unrecognized tax benefits	2020	2019	2018
	(millions of dollars)
Balance at January 1	8,844	9,174	8,783
Additions based on current year's tax positions	253	287	375
Additions for prior years' tax positions	218	120	240
Reductions for prior years' tax positions	(201)	(97)	(125)
Reductions due to lapse of the statute of limitations	(237)	(279)	(5)
Settlements with tax authorities	(113)	(538)	(68)
Foreign exchange effects/other	—	177	(26)
Balance at December 31	8,764	8,844	9,174

The gross unrecognized tax benefit balances shown above are predominantly related to tax positions that would reduce the Corporation’s effective tax rate if the positions are favorably resolved. Unfavorable resolution of these tax positions generally would not increase the effective tax rate. The 2020, 2019 and 2018 changes in unrecognized tax benefits did not have a material effect on the Corporation’s net income.

Resolution of these tax positions through negotiations with the relevant tax authorities or through litigation will take many years to complete. It is difficult to predict the timing of resolution for tax positions since such timing is not entirely within the control of the Corporation. In the United States, the Corporation has various ongoing U.S. federal income tax positions at issue with the Internal Revenue Service (IRS) for tax years beginning in 2006. The Corporation filed a refund suit for tax years 2006-2009 in U.S. federal district court (District Court) with respect to the positions at issue for those years. These positions are reflected in the unrecognized tax benefits table above. On February 24, 2020, the Corporation received an adverse ruling on this suit. The IRS has asserted penalties associated with several of those positions. The Corporation has not recognized the penalties as an expense because the Corporation does not expect the penalties to be sustained under applicable law. On January 13, 2021, the District Court ruled that no penalties apply to the Corporation's positions in this suit. Proceedings in the District Court are continuing. Unfavorable resolution of all positions at issue with the IRS would not have a material adverse effect on the Corporation’s operations or financial condition.

It is reasonably possible that the total amount of unrecognized tax benefits could increase or decrease by 10 percent in the next 12 months.

The following table summarizes the tax years that remain subject to examination by major tax jurisdiction:


Country of Operation	Open Tax Years
Abu Dhabi	2018	—	2020
Angola	2018	—	2020
Australia	2010	—	2020
Belgium	2017	—	2020
Canada	2001	—	2020
Equatorial Guinea	2007	—	2020
Indonesia	2007	—	2020
Iraq	2015	—	2020
Malaysia	2011	—	2020
Nigeria	2006	—	2020
Norway	2010	—	2020
Papua New Guinea	2008	—	2020
Russia	2018	—	2020
United Kingdom	2015	—	2020
United States	2006	—	2020

The Corporation classifies interest on income tax-related balances as interest expense or interest income and classifies tax-related penalties as operating expense.

For 2020, the Corporation's net interest expense was a credit of $6 million on income tax reserves. The Corporation incurred $0 million and $3 million in interest expense on income tax reserves in 2019 and 2018, respectively. The related interest payable balances were $61 million and $71 million at December 31, 2020, and 2019, respectively.

Restructuring Activities

12 Months Ended

Dec. 31, 2020

Restructuring and Related Activities [Abstract]

Restructuring and Related Activities Disclosure

Restructuring Activities

During 2020, ExxonMobil conducted an extensive global review of staffing levels and subsequently commenced targeted workforce reductions within a number of countries to improve efficiency and reduce costs. The programs, which are expected to be substantially completed by the end of 2021, include both voluntary and involuntary employee separations and reductions in contractors.

In 2020 the Corporation recorded before-tax charges of $450 million, consisting primarily of employee separation costs, associated with announced workforce reduction programs in Europe, North America, and Australia. These costs are captured in “Selling, general and administrative expenses” on the Statement of Income and reported in the Corporate and financing segment. The Corporation estimates additional charges of up to $200 million in 2021 related to planned workforce reduction programs.

The following table summarizes the reserves and charges related to the workforce reduction programs, which are recorded in “Accounts payable and accrued liabilities.”


			2020
			(millions of dollars)
Balance at January 1			—
Additions/adjustments			450
Payments made			(47)
Balance at December 31			403

Summary Of Accounting Policies (Policy)	12 Months Ended
Summary Of Accounting Policies (Policy)	Dec. 31, 2020
Accounting Policies [Abstract]
Principles of Consolidation and Accounting for Investments	Principles of Consolidation and Accounting for Investments The Consolidated Financial Statements include the accounts of subsidiaries the Corporation controls. They also include the Corporation’s share of the undivided interest in certain upstream assets, liabilities, revenues and expenses. Amounts representing the Corporation’s interest in entities that it does not control, but over which it exercises significant influence, are included in “Investments, advances and long-term receivables”. The Corporation’s share of the net income of these companies is included in the Consolidated Statement of Income caption “Income from equity affiliates”. Majority ownership is normally the indicator of control that is the basis on which subsidiaries are consolidated. However, certain factors may indicate that a majority-owned investment is not controlled and therefore should be accounted for using the equity method of accounting. These factors occur where the minority shareholders are granted by law or by contract substantive participating rights. These include the right to approve operating policies, expense budgets, financing and investment plans, and management compensation and succession plans. Evidence of loss in value that might indicate impairment of investments in companies accounted for on the equity method is assessed to determine if such evidence represents a loss in value that is other than temporary. Examples of key indicators include a history of operating losses, negative earnings and cash flow outlook, significant downward revisions to oil and gas reserves, and the financial condition and prospects for the investee’s business segment or geographic region. If evidence of an other than temporary loss in fair value below carrying amount is determined, an impairment is recognized. In the absence of market prices for the investment, discounted cash flows are used to assess fair value. Investments in equity securities other than consolidated subsidiaries and equity method investments are measured at fair value with changes in fair value recognized in net income. The Corporation uses the modified approach for equity securities that do not have a readily determinable fair value. This modified approach measures investments at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions in a similar investment of the same issuer. The Corporation’s share of the cumulative foreign exchange translation adjustment for equity method investments is reported in “Accumulated other comprehensive income”.
Revenue Recognition	Revenue Recognition The Corporation generally sells crude oil, natural gas and petroleum and chemical products under short-term agreements at prevailing market prices. In some cases (e.g., natural gas), products may be sold under long-term agreements, with periodic price adjustments to reflect market conditions. Revenue is recognized at the amount the Corporation expects to receive when the customer has taken control, which is typically when title transfers and the customer has assumed the risks and rewards of ownership. The prices of certain sales are based on price indices that are sometimes not available until the next period. In such cases, estimated realizations are accrued when the sale is recognized, and are finalized when the price is available. Such adjustments to revenue from performance obligations satisfied in previous periods are not significant. Payment for revenue transactions is typically due within 30 days. Future volume delivery obligations that are unsatisfied at the end of the period are expected to be fulfilled through ordinary production or purchases. These performance obligations are based on market prices at the time of the transaction and are fully constrained due to market price volatility. Purchases and sales of inventory with the same counterparty that are entered into in contemplation of one another are combined and recorded as exchanges measured at the book value of the item sold. “Sales and other operating revenue” and “Notes and accounts receivable” primarily arise from contracts with customers. Long-term receivables are primarily from non-customers. Contract assets are mainly from marketing assistance programs and are not significant. Contract liabilities are mainly customer prepayments and accruals of expected volume discounts and are not significant.
Income and Other Taxes	Income and Other Taxes The Corporation excludes from the Consolidated Statement of Income certain sales and value-added taxes imposed on and concurrent with revenue-producing transactions with customers and collected on behalf of governmental authorities. Similar taxes, for which the Corporation is not considered to be an agent for the government, are reported on a gross basis (included in both “Sales and other operating revenue” and “Other taxes and duties”). The Corporation accounts for U.S. tax on global intangible low-taxed income as an income tax expense in the period in which it is incurred.
Derivative Instruments	Derivative Instruments The Corporation may use derivative instruments for trading purposes and to offset exposures associated with commodity prices, foreign currency exchange rates and interest rates that arise from existing assets, liabilities, firm commitments and forecasted transactions. All derivative instruments, except those designated as normal purchase and normal sale, are recorded at fair value. Derivative assets and liabilities with the same counterparty are netted if the right of offset exists and certain other criteria are met. Collateral payables or receivables are netted against derivative assets and derivative liabilities, respectively. Recognition and classification of the gain or loss that results from adjusting a derivative to fair value depends on the purpose for the derivative. All gains and losses from derivative instruments for which the Corporation does not apply hedge accounting are immediately recognized in earnings. The Corporation may designate derivatives as fair value or cash flow hedges. For fair value hedges, the gain or loss from derivative instruments and the offsetting gain or loss from the hedged item are recognized in earnings. For cash flow hedges, the gain or loss from the derivative instrument is initially reported as a component of other comprehensive income and subsequently reclassified into earnings in the period that the forecasted transaction affects earnings.
Fair Value	Fair Value Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Hierarchy Levels 1, 2 and 3 are terms for the priority of inputs to valuation techniques used to measure fair value. Hierarchy Level 1 inputs are quoted prices in active markets for identical assets or liabilities. Hierarchy Level 2 inputs are inputs other than quoted prices included within Level 1 that are directly or indirectly observable for the asset or liability. Hierarchy Level 3 inputs are inputs that are not observable in the market.
Inventories	Inventories Crude oil, products and merchandise inventories are carried at the lower of current market value or cost (generally determined under the last-in, first-out method – LIFO). Inventory costs include expenditures and other charges (including depreciation) directly and indirectly incurred in bringing the inventory to its existing condition and location. Selling expenses and general and administrative expenses are reported as period costs and excluded from inventory cost. Inventories of materials and supplies are valued at cost or less.
Property, Plant And Equipment	Property, Plant and Equipment Cost Basis. The Corporation uses the “successful efforts” method to account for its exploration and production activities. Under this method, costs are accumulated on a field-by-field basis. Costs incurred to purchase, lease, or otherwise acquire a property (whether unproved or proved) are capitalized when incurred. Exploratory well costs are carried as an asset when the well has found a sufficient quantity of reserves to justify its completion as a producing well and where the Corporation is making sufficient progress assessing the reserves and the economic and operating viability of the project. Exploratory well costs not meeting these criteria are charged to expense. Other exploratory expenditures, including geophysical costs and annual lease rentals, are expensed as incurred. Development costs, including costs of productive wells and development dry holes, are capitalized. Depreciation, Depletion and Amortization. Depreciation, depletion and amortization are primarily determined under either the unit-of-production method or the straight-line method, which is based on estimated asset service life taking obsolescence into consideration. Acquisition costs of proved properties are amortized using a unit-of-production method, computed on the basis of total proved oil and natural gas reserve volumes. Capitalized exploratory drilling and development costs associated with productive depletable extractive properties are amortized using the unit-of-production rates based on the amount of proved developed reserves of oil and gas that are estimated to be recoverable from existing facilities using current operating methods. Under the unit-of-production method, oil and natural gas volumes are considered produced once they have been measured through meters at custody transfer or sales transaction points at the outlet valve on the lease or field storage tank. In the event that the unit-of-production method does not result in an equitable allocation of cost over the economic life of an upstream asset, an alternative method is used. The straight-line method is used in limited situations where the expected life of the asset does not reasonably correlate with that of the underlying reserves. For example, certain assets used in the production of oil and natural gas have a shorter life than the reserves, and as such, the Corporation uses straight-line depreciation to ensure the asset is fully depreciated by the end of its useful life. To the extent that proved reserves for a property are substantially de-booked and that property continues to produce such that the resulting depreciation charge does not result in an equitable allocation of cost over the expected life, assets will be depreciated using a unit-of-production method based on reserves determined at the most recent SEC price which results in a more meaningful quantity of proved reserves, appropriately adjusted for production and technical changes. Investments in refinery, chemical process, and lubes basestock manufacturing equipment are generally depreciated on a straight-line basis over a 25-year life. Service station buildings and fixed improvements generally are depreciated over a 20-year life. Maintenance and repairs, including planned major maintenance, are expensed as incurred. Major renewals and improvements are capitalized and the assets replaced are retired. Impairment Assessment. The Corporation tests assets or groups of assets for recoverability on an ongoing basis whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. Among the events or changes in circumstances which could indicate that the carrying value of an asset or asset group may not be recoverable are the following: •a significant decrease in the market price of a long-lived asset; •a significant adverse change in the extent or manner in which an asset is being used or in its physical condition including a significant decrease in current and projected reserve volumes; •a significant adverse change in legal factors or in the business climate that could affect the value, including an adverse action or assessment by a regulator; •an accumulation of project costs significantly in excess of the amount originally expected; •a current-period operating loss combined with a history and forecast of operating or cash flow losses; and •a current expectation that, more likely than not, a long-lived asset will be sold or otherwise disposed of significantly before the end of its previously estimated useful life. Asset valuation analysis, profitability reviews and other periodic control processes assist the Corporation in assessing whether events or changes in circumstances indicate the carrying amounts of any of its assets may not be recoverable. In general, the Corporation does not view temporarily low prices or margins as an indication of impairment. Management believes that prices over the long term must be sufficient to generate investments in energy supply to meet global demand. Although prices will occasionally drop significantly, industry prices over the long term will continue to be driven by market supply and demand fundamentals. On the supply side, industry production from mature fields is declining. This is being offset by investments to generate production from new discoveries, field developments and technology and efficiency advancements. OPEC investment activities and production policies also have an impact on world oil supplies. The demand side is largely a function of general economic activities and levels of prosperity. Because the lifespans of the vast majority of the Corporation’s major assets are measured in decades, the value of these assets is predominantly based on long-term views of future commodity prices and development and production costs. During the lifespan of these major assets, the Corporation expects that oil and gas prices will experience significant volatility, and consequently these assets will experience periods of higher earnings and periods of lower earnings, or even losses. In assessing whether events or changes in circumstances indicate the carrying value of an asset may not be recoverable, the Corporation considers recent periods of operating losses in the context of its longer-term view of prices. While near-term prices are subject to wide fluctuations, longer-term price views are more stable and meaningful for purposes of assessing future cash flows. When the industry experiences a prolonged and deep reduction in commodity prices, the market supply and demand conditions may result in changes to the Corporation’s price or margin assumptions it uses for its capital investment decisions. To the extent those changes result in a significant reduction to its oil price, natural gas price or margin ranges, the Corporation may consider that situation, in conjunction with other events or changes in circumstances such as a history of operating losses, an indicator of potential impairment for certain assets. In the Upstream, the standardized measure of discounted cash flows included in the Supplemental Information on Oil and Gas Exploration and Production Activities is required to use prices based on the average of first-of-month prices. These prices represent discrete points in time and could be higher or lower than the Corporation’s price assumptions which are used for impairment assessments. The Corporation believes the standardized measure does not provide a reliable estimate of the expected future cash flows to be obtained from the development and production of its oil and gas properties or of the value of its oil and gas reserves and therefore does not consider it relevant in determining whether events or changes in circumstances indicate the need for an impairment assessment. The Corporation has a robust process to monitor for indicators of potential impairment across its asset groups throughout the year. This process is aligned with the requirements of ASC 360 and ASC 932, and relies in part on the Corporation’s planning and budgeting cycle. If events or changes in circumstances indicate that the carrying value of an asset may not be recoverable, the Corporation estimates the future undiscounted cash flows of the affected properties to judge the recoverability of carrying amounts. In performing this assessment, assets are grouped at the lowest level for which there are identifiable cash flows that are largely independent of the cash flows of other groups of assets. Cash flows used in recoverability assessments are based on the Corporation’s assumptions which are developed in the annual planning and budgeting process, and are consistent with the criteria management uses to evaluate investment opportunities. These evaluations make use of the Corporation’s assumptions of future capital allocations, crude oil and natural gas commodity prices including price differentials, refining and chemical margins, volumes, development and operating costs, and foreign currency exchange rates. Volumes are based on projected field and facility production profiles, throughput, or sales. Management’s estimate of upstream production volumes used for projected cash flows makes use of proved reserve quantities and may include risk-adjusted unproved reserve quantities. Cash flow estimates for impairment testing exclude the effects of derivative instruments. An asset group is impaired if its estimated undiscounted cash flows are less than the asset’s carrying value. Impairments are measured by the amount by which the carrying value exceeds fair value. Fair value is based on market prices if an active market exists for the asset group, or discounted cash flows using a discount rate commensurate with the risk. Unproved properties are assessed periodically to determine whether they have been impaired. Significant unproved properties are assessed for impairment individually, and valuation allowances against the capitalized costs are recorded based on the Corporation's future development plans, the estimated economic chance of success and the length of time that the Corporation expects to hold the properties. Properties that are not individually significant are aggregated by groups and amortized based on development risk and average holding period. Other. Gains on sales of proved and unproved properties are only recognized when there is neither uncertainty about the recovery of costs applicable to any interest retained nor any substantial obligation for future performance by the Corporation. Losses on properties sold are recognized when incurred or when the properties are held for sale and the fair value of the properties is less than the carrying value. Interest costs incurred to finance expenditures during the construction phase of multiyear projects are capitalized as part of the historical cost of acquiring the constructed assets. The project construction phase commences with the development of the detailed engineering design and ends when the constructed assets are ready for their intended use. Capitalized interest costs are included in property, plant and equipment and are depreciated over the service life of the related assets.
Environmental Liabilities	Environmental Liabilities Liabilities for environmental costs are recorded when it is probable that obligations have been incurred and the amounts can be reasonably estimated. These liabilities are not reduced by possible recoveries from third parties, and projected cash expenditures are not discounted.
Foreign Currency Translation	Foreign Currency Translation The Corporation selects the functional reporting currency for its international subsidiaries based on the currency of the primary economic environment in which each subsidiary operates. Downstream and Chemical operations primarily use the local currency. However, the U.S. dollar is used in countries with a history of high inflation (primarily in Latin America) and Singapore, which predominantly sells into the U.S. dollar export market. Upstream operations which are relatively self-contained and integrated within a particular country, such as Canada, the United Kingdom and continental Europe, use the local currency. Some Upstream operations, primarily in Asia and Africa, use the U.S. dollar because they predominantly sell crude and natural gas production into U.S. dollar-denominated markets. For all operations, gains or losses from remeasuring foreign currency transactions into the functional currency are included in income.
Credit Loss Financial Instrument	The Corporation groups financial assets into portfolios that share similar risk characteristics for purposes of determining the allowance for credit losses and assesses if a significant change in the risk of credit loss has occurred. Among the quantitative and qualitative factors considered are historical financial data, current conditions, industry and country risk, current credit ratings and the quality of third-party guarantees secured from the counterparty. Financial assets are written off in whole, or in part, when practical recovery efforts have been exhausted and no reasonable expectation of recovery exists. Subsequent recoveries of amounts previously written off are recognized in earnings. The Corporation manages receivable portfolios using past due balances as a key credit quality indicator.The Corporation recognizes a credit allowance for off-balance sheet credit exposures as a liability on the balance sheet, separate from the allowance for credit losses related to recognized financial assets.
Asset Retirement Obligations	The Corporation incurs retirement obligations for certain assets. The fair values of these obligations are recorded as liabilities on a discounted basis, which is typically at the time the assets are installed. In the estimation of fair value, the Corporation uses assumptions and judgments regarding such factors as the existence of a legal obligation for an asset retirement obligation; technical assessments of the assets; estimated amounts and timing of settlements; discount rates; and inflation rates. Asset retirement obligations incurred in the current period were Level 3 fair value measurements. The costs associated with these liabilities are capitalized as part of the related assets and depreciated as the reserves are produced. Over time, the liabilities are accreted for the change in their present value.
Leases	Right of use assets and lease liabilities are established on the balance sheet for leases with an expected term greater than one year by discounting the amounts fixed in the lease agreement for the duration of the lease which is reasonably certain, considering the probability of exercising any early termination and extension options. The portion of the fixed payment related to service costs for drilling equipment, tankers and finance leases is excluded from the calculation of right of use assets and lease liabilities.In general, leases are capitalized using the incremental borrowing rate of the leasing affiliate.
Net Investment Hedge Risk Management	The Corporation may use non-derivative financial instruments, such as its foreign currency-denominated debt, as hedges of its net investments in certain foreign subsidiaries. Under this method, the change in the carrying value of the financial instruments due to foreign exchange fluctuations is reported in accumulated other comprehensive income.
Stock-Based Payments	Compensation expense for these awards is based on the price of the stock at the date of grant and is recognized in income over the requisite service period. Shares for these awards are issued to employees from treasury stock. The units that are settled in cash are recorded as liabilities and their changes in fair value are recognized over the vesting period

Accounting Changes (Tables)

12 Months Ended

Dec. 31, 2020

New Accounting Pronouncements and Changes in Accounting Principles [Abstract]

Allowance for Credit Loss


	Allowance for Current Expected Credit Losses
	Notes and Accounts Receivable		Advances and Long-Term Receivables	Liabilities for Off- Balance Sheet Assets
	Trade	Other			Total
	(millions of dollars)
Balance at December 31, 2019	34	56	413	—	503
Cumulative effect of accounting change	52	6	39	12	109
Current period provision	9	15	(9)	(1)	14
Write-offs charged against the allowance	(2)	(3)	—	—	(5)
Other	2	(3)	3	—	2
Balance at December 31, 2020	95	71	446	11	623

Balance at December 31, 2020
Financial Assets subject to credit losses standard - net	16,250	1,962	9,447

Miscellaneous Financial Information (Tables)

12 Months Ended

Dec. 31, 2020

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Crude Oil, Products And Merchandise

Crude oil, products and merchandise as of year-end 2020 and 2019 consist of the following:


	Dec 31, 2020	Dec 31, 2019
	(millions of dollars)
Crude oil	5,354	5,111
Petroleum products	5,138	5,281
Chemical products	3,023	3,240
Gas/other	654	378
Total	14,169	14,010

Other Comprehensive Income Information (Tables)

12 Months Ended

Dec. 31, 2020

Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]

Schedule Of Accumulated Other Comprehensive Income Information


ExxonMobil Share of Accumulated Other Comprehensive Income	Cumulative Foreign Exchange Translation Adjustment	Postretirement Benefits Reserves Adjustment	Total
	(millions of dollars)
Balance as of December 31, 2017	(9,482)	(6,780)	(16,262)
Current period change excluding amounts reclassified from accumulated other comprehensive income	(4,595)	201	(4,394)
Amounts reclassified from accumulated other comprehensive income	196	896	1,092
Total change in accumulated other comprehensive income	(4,399)	1,097	(3,302)
Balance as of December 31, 2018	(13,881)	(5,683)	(19,564)

Current period change excluding amounts reclassified from accumulated other comprehensive income	1,435	(1,927)	(492)
Amounts reclassified from accumulated other comprehensive income	—	563	563
Total change in accumulated other comprehensive income	1,435	(1,364)	71
Balance as of December 31, 2019	(12,446)	(7,047)	(19,493)

Current period change excluding amounts reclassified from accumulated other comprehensive income (1)	1,818	95	1,913
Amounts reclassified from accumulated other comprehensive income	14	861	875
Total change in accumulated other comprehensive income	1,832	956	2,788
Balance as of December 31, 2020	(10,614)	(6,091)	(16,705)

(1) Cumulative Foreign Exchange Translation Adjustment includes net investment hedge gain/(loss) of $(355) million, net of taxes.

Reclassification Out Of Accumulated Other Comprehensive Income


Amounts Reclassified Out of Accumulated Other Comprehensive Income - Before-tax Income/(Expense)	2020	2019	2018
	(millions of dollars)
Foreign exchange translation gain/(loss) included in net income (Statement of Income line: Other income)	(14)	—	(196)
Amortization and settlement of postretirement benefits reserves adjustment included in net periodic benefit costs (Statement of Income line: Non-service pension and postretirement benefit expense)	(1,158)	(751)	(1,208)

Schedule Of Income Tax (Expense)/Credit For Components Of Other Comprehensive Income


Income Tax (Expense)/Credit For Components of Other Comprehensive Income	2020	2019	2018
	(millions of dollars)
Foreign exchange translation adjustment	118	88	32
Postretirement benefits reserves adjustment (excluding amortization)	109	719	(193)
Amortization and settlement of postretirement benefits reserves adjustment included in net periodic benefit costs	(262)	(169)	(277)
Total	(35)	638	(438)

Cash Flow Information (Tables)

12 Months Ended

Dec. 31, 2020

Supplemental Cash Flow Information [Abstract]

Cash Payments For Interest And Income Taxes


	2020	2019	2018
	(millions of dollars)
Income taxes paid	2,428	7,018	9,294
Cash interest paid
Included in cash flows from operating activities	786	560	303
Capitalized, included in cash flows from investing activities	665	731	652
Total cash interest paid	1,451	1,291	955

Additional Working Capital Information (Tables)

12 Months Ended

Dec. 31, 2020

Additional Working Capital Information [Abstract]

Schedule Of Notes, Accounts Receivable And Payable, Loans Payable, And Accrued Liabilities


	Dec 31, 2020	Dec 31, 2019
	(millions of dollars)
Notes and accounts receivable
Trade, less reserves of $96 million and $34 million	16,339	21,100
Other, less reserves of $378 million and $371 million	4,242	5,866
Total	20,581	26,966
Notes and loans payable
Bank loans	222	316
Commercial paper	17,306	18,561
Long-term debt due within one year	2,930	1,701
Total	20,458	20,578
Accounts payable and accrued liabilities
Trade payables	17,499	24,694
Payables to equity companies	6,476	6,825
Accrued taxes other than income taxes	3,408	3,301
Other	7,838	7,011
Total	35,221	41,831

Equity Company Information (Tables)

12 Months Ended

Dec. 31, 2020

Equity Method Investment, Financial Statement, Reported Amounts [Abstract]

Schedule Of Equity Company Financial Summary


	2020		2019		2018
Equity Company Financial Summary	Total	ExxonMobil Share	Total	ExxonMobil Share	Total	ExxonMobil Share
	(millions of dollars)
Total revenues	69,954	21,282	102,365	31,240	112,938	34,539
Income before income taxes	12,743	2,830	29,424	7,927	37,203	10,482
Income taxes	4,333	870	9,725	2,500	11,568	3,151
Income from equity affiliates	8,410	1,960	19,699	5,427	25,635	7,331

Current assets	33,419	11,969	36,035	12,661	38,670	13,394
Long-term assets	150,358	41,457	143,321	40,001	128,830	35,970
Total assets	183,777	53,426	179,356	52,662	167,500	49,364
Current liabilities	18,827	5,245	24,583	6,939	27,324	7,606
Long-term liabilities	66,053	19,927	61,022	18,158	56,913	17,109
Net assets	98,897	28,254	93,751	27,565	83,263	24,649

Schedule Of The Corporation's Percentage Ownership Interest

A list of significant equity companies as of December 31, 2020, together with the Corporation’s percentage ownership interest, is detailed below:


			Percentage Ownership Interest
Upstream
Aera Energy LLC			48
Barzan Gas Company Limited			7
BEB Erdgas und Erdoel GmbH & Co. KG			50
Cameroon Oil Transportation Company S.A.			41
Caspian Pipeline Consortium - Kazakhstan			8
CORAL FLNG, S.A.			25
Cross Timbers Energy, LLC			50
Golden Pass LNG Terminal LLC			30
Golden Pass Pipeline LLC			30
Marine Well Containment Company LLC			10
Mozambique Rovuma Venture, S.p.A.			36
Nederlandse Aardolie Maatschappij B.V.			50
Papua New Guinea Liquefied Natural Gas Global Company LDC			33
Permian Highway Pipeline LLC			20
Qatar Liquefied Gas Company Limited			10
Qatar Liquefied Gas Company Limited (2)			24
Ras Laffan Liquefied Natural Gas Company Limited			25
Ras Laffan Liquefied Natural Gas Company Limited (II)			31
Ras Laffan Liquefied Natural Gas Company Limited (3)			30
South Hook LNG Terminal Company Limited			24
Tengizchevroil, LLP			25
Terminale GNL Adriatico S.r.l.			71

Downstream
Alberta Products Pipe Line Ltd.			45
Fujian Refining & Petrochemical Co. Ltd.			25
Permian Express Partners LLC			12
Saudi Aramco Mobil Refinery Company Ltd.			50

Chemical
Al-Jubail Petrochemical Company			50
Gulf Coast Growth Ventures LLC			50
Saudi Yanbu Petrochemical Co.			50

Investments, Advances And Long-Term Receivables (Tables)

12 Months Ended

Dec. 31, 2020

Long-term Investments and Receivables, Net [Abstract]

Schedule Of Investments, Advances And Long-Term Receivables


	Dec 31, 2020	Dec 31, 2019
	(millions of dollars)
Equity method company investments and advances
Investments	29,772	29,291
Advances, net of allowances of $31 million in 2020	8,812	8,542
Total equity method company investments and advances	38,584	37,833
Equity securities carried at fair value and other investments at adjusted cost basis	143	190
Long-term receivables and miscellaneous, net of reserves of $6,115 million and $5,643 million	4,788	5,141
Total	43,515	43,164

Property, Plant And Equipment And Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2020

Property, Plant And Equipment And Asset Retirement Obligations [Abstract]

Property, Plant And Equipment


	December 31, 2020		December 31, 2019
Property, Plant and Equipment	Cost	Net	Cost	Net
	(millions of dollars)
Upstream	386,614	167,472	376,041	196,767
Downstream	57,922	27,716	52,527	24,506
Chemical	42,868	21,924	40,788	21,260
Other	17,918	10,441	17,346	10,485
Total	505,322	227,553	486,702	253,018

Asset Retirement Obligations

The following table summarizes the activity in the liability for asset retirement obligations:


	2020	2019	2018
	(millions of dollars)
Balance at January 1	11,280	12,103	12,705
Accretion expense and other provisions	584	649	681
Reduction due to property sales	(77)	(1,085)	(333)
Payments made	(669)	(827)	(600)
Liabilities incurred	26	89	46
Foreign currency translation	239	84	(481)
Revisions	(136)	267	85
Balance at December 31	11,247	11,280	12,103

Accounting For Suspended Exploratory Well Costs (Tables)

12 Months Ended

Dec. 31, 2020

Capitalized Exploratory Well Costs [Abstract]

Change In Capitalized Suspended Exploratory Well Costs

Change in capitalized suspended exploratory well costs:


	2020	2019	2018
	(millions of dollars)
Balance beginning at January 1	4,613	4,160	3,700
Additions pending the determination of proved reserves	208	532	564
Charged to expense	(318)	(46)	(7)
Reclassifications to wells, facilities and equipment based on the determination of proved reserves	(174)	(37)	(48)
Divestments/Other	53	4	(49)
Ending balance at December 31	4,382	4,613	4,160
Ending balance attributed to equity companies included above	306	306	306

Period End Capitalized Suspended Exploratory Well Costs

Period end capitalized suspended exploratory well costs:


	2020	2019	2018
	(millions of dollars)
Capitalized for a period of one year or less	208	532	564
Capitalized for a period of between one and five years	1,828	2,206	2,028
Capitalized for a period of between five and ten years	1,932	1,411	1,150
Capitalized for a period of greater than ten years	414	464	418
Capitalized for a period greater than one year - subtotal	4,174	4,081	3,596
Total	4,382	4,613	4,160

Number Of Projects With Suspended Exploratory Well Costs


	2020	2019	2018
Number of projects that only have exploratory well costs capitalized for a period of one year or less	3	4	6
Number of projects that have exploratory well costs capitalized for a period greater than one year	34	46	52
Total	37	50	58

Additional Detail For Projects With Completed Exploratory Activity Progressing Toward Development

The table below provides additional detail for those 21 projects, which total $3,181 million.


Country/Project	Dec. 31, 2020	Years Wells Drilled / Acquired			Comment
(millions of dollars)
Angola
–Kaombo Split Hub Phase 2	10	2006			Evaluating development plan to tie into planned production facilities.
Argentina
–La Invernada	72	2014			Evaluating development plan to tie into planned infrastructure.
Australia
–Gorgon Area Ullage	347	1994	-	2015	Evaluating development plans to tie into existing LNG facilities.
Brazil
–Bacalhau Phase 1	284	2018			Continuing discussions with the government regarding development plan.
Canada
–Hibernia North	26	2019			Awaiting capacity in existing/planned infrastructure.
Iraq
–Kurdistan Pirmam	109	2015			Evaluating commercialization alternatives, while waiting for government approval to enter Gas Holding Period.
Kazakhstan
–Kairan	53	2004	-	2007	Evaluating commercialization and field development alternatives, while continuing discussions with the government regarding the development plan.
Mozambique
–Rovuma LNG Future Non-Straddling Train	120	2017			Evaluating/progressing development plan to tie into planned LNG facilities.
–Rovuma LNG Phase 1	150	2017			Progressing development plan to tie into planned LNG facilities.
–Rovuma LNG Unitized Trains	35	2017			Evaluating/progressing development plan to tie into planned LNG facilities.
Nigeria
–Bonga North	34	2004	-	2009	Evaluating/progressing development plan for tieback to existing/planned infrastructure.
–Bonga SW	3	2001			Evaluating/progressing development plan for tieback to existing/planned infrastructure.
–Bosi	79	2002	-	2006	Development activity under way, while continuing discussions with the government regarding development plan.
–Owowo	67	2009	-	2016	Evaluating development plan for tieback to existing production facilities.
–Pegi	32	2009			Awaiting capacity in existing/planned infrastructure.
–Ukot SW	41	2014			Evaluating development plan for tieback to existing production facilities.
Papua New Guinea
–Papua LNG	246	2017			Evaluating/progressing development plans.
–P'nyang	116	2012	-	2018	Evaluating/progressing development plans.
Romania
–Neptun Deep	536	2012	-	2016	Continuing discussions with the government regarding development plan.
Tanzania
–Tanzania Block 2	525	2012	-	2015	Evaluating development alternatives, while continuing discussions with the government regarding development plan.
Vietnam
–Blue Whale	296	2011	-	2015	Evaluating/progressing development plans.
Total 2020 (21 projects)	3,181

Leases (Tables)

12 Months Ended

Dec. 31, 2020

Leases [Abstract]

Lease Cost


	Operating Leases
	Drilling Rigs and Related Equipment	Other	Total	Finance Leases
	(millions of dollars)
Lease Cost	2020
Operating lease cost	297	1,256	1,553
Short-term and other (net of sublease rental income)	530	1,083	1,613
Amortization of right of use assets				143
Interest on lease liabilities				169
Total	827	2,339	3,166	312


	Operating Leases
	Drilling Rigs and Related Equipment	Other	Total	Finance Leases
	(millions of dollars)
Lease Cost	2019
Operating lease cost	238	1,196	1,434
Short-term and other (net of sublease rental income)	926	1,116	2,042
Amortization of right of use assets				121
Interest on lease liabilities				133
Total	1,164	2,312	3,476	254

Right Of Use Assets And Lease Liabilities


	Operating Leases
	Drilling Rigs and Related Equipment		Other		Total		Finance Leases
	(millions of dollars)
Balance Sheet	December 31, 2020
Right of use assets
Included in Other assets, including intangibles - net	834		5,244		6,078
Included in Property, plant and equipment - net							2,188
Total right of use assets	834		5,244		6,078		2,188

Lease liability due within one year
Included in Accounts payable and accrued liabilities	243		925		1,168		4
Included in Notes and loans payable							102
Long-term lease liability
Included in Other long-term obligations	589		3,405		3,994
Included in Long-term debt							1,680
Included in Long-term obligations to equity companies							135
Total lease liability	832		4,330		5,162		1,921

Weighted average remaining lease term - years	5		12		11		20
Weighted average discount rate - percent	2.2	%	3.0	%	2.9	%	8.9	%


	Operating Leases
	Drilling Rigs and Related Equipment		Other		Total		Finance Leases
	(millions of dollars)
Balance Sheet	December 31, 2019
Right of use assets
Included in Other assets, including intangibles - net	572		6,061		6,633
Included in Property, plant and equipment - net							1,997
Total right of use assets	572		6,061		6,633		1,997

Lease liability due within one year
Included in Accounts payable and accrued liabilities	221		990		1,211		15
Included in Notes and loans payable							84
Long-term lease liability
Included in Other long-term obligations	330		4,152		4,482
Included in Long-term debt							1,670
Included in Long-term obligations to equity companies							139
Total lease liability	551		5,142		5,693		1,908

Weighted average remaining lease term - years	4		11		10		20
Weighted average discount rate - percent	3.1	%	3.2	%	3.2	%	9.7	%

Maturity Analysis of Operating Leases


	Operating Leases
	Drilling Rigs and Related Equipment	Other	Total	Finance Leases
	(millions of dollars)
Maturity Analysis of Lease Liabilities	December 31, 2020
2021	259	1,031	1,290	268
2022	256	817	1,073	259
2023	97	482	579	252
2024	71	387	458	247
2025	71	342	413	240
2026 and beyond	124	2,157	2,281	2,544
Total lease payments	878	5,216	6,094	3,810
Discount to present value	(46)	(886)	(932)	(1,889)
Total lease liability	832	4,330	5,162	1,921

Maturity Analysis of Finance Leases


	Operating Leases
	Drilling Rigs and Related Equipment	Other	Total	Finance Leases
	(millions of dollars)
Maturity Analysis of Lease Liabilities	December 31, 2020
2021	259	1,031	1,290	268
2022	256	817	1,073	259
2023	97	482	579	252
2024	71	387	458	247
2025	71	342	413	240
2026 and beyond	124	2,157	2,281	2,544
Total lease payments	878	5,216	6,094	3,810
Discount to present value	(46)	(886)	(932)	(1,889)
Total lease liability	832	4,330	5,162	1,921

Operating And Finance Leases Other Information


	Operating Leases
	Drilling Rigs and Related Equipment	Other	Total	Finance Leases
	(millions of dollars)
Other Information	2020
Cash paid for amounts included in the measurement of lease liabilities
Cash flows from operating activities		1,159	1,159	31
Cash flows from investing activities	283		283
Cash flows from financing activities				94

Noncash right of use assets recorded in exchange for lease liabilities	552	183	735	108


	Operating Leases
	Drilling Rigs and Related Equipment	Other	Total	Finance Leases
	(millions of dollars)
Other Information	2019
Cash paid for amounts included in the measurement of lease liabilities
Cash flows from operating activities		1,116	1,116	54
Cash flows from investing activities	258		258
Cash flows from financing activities				177

Noncash right of use assets recorded for lease liabilities
For January 1 adoption of ASC 842	445	2,818	3,263
In exchange for lease liabilities during the period	350	3,313	3,663	422

Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Earnings Per Share Computation


Earnings per common share	2020	2019	2018
Net income (loss) attributable to ExxonMobil (millions of dollars)	(22,440)	14,340	20,840

Weighted average number of common shares outstanding (millions of shares)	4,271	4,270	4,270

Earnings (Loss) per common share (dollars) (1)	(5.25)	3.36	4.88

Dividends paid per common share (dollars)	3.48	3.43	3.23

(1)The earnings (loss) per common share and earnings (loss) per common share - assuming dilution are the same in each period shown.

Financial Instruments and Derivatives (Tables)

12 Months Ended

Dec. 31, 2020

Financial Instruments And Derivatives [Abstract]

Financial Instruments

The estimated fair value of financial instruments at December 31, 2020 and December 31, 2019, and the related hierarchy level for the fair value measurement is as follows:


	At December 31, 2020
	(millions of dollars)
	Fair Value
	Level 1	Level 2	Level 3	Total Gross Assets & Liabilities	Effect of Counterparty Netting	Effect of Collateral Netting	Difference in Carrying Value and Fair Value	Net Carrying Value
Assets
Derivative assets (1)	1,247	194	—	1,441	(1,282)	(6)	—	153
Advances to/receivables from equity companies (2)(6)	—	3,275	5,904	9,179	—	—	(367)	8,812
Other long-term financial assets (3)	1,235	—	944	2,179	—	—	125	2,304

Liabilities
Derivative liabilities (4)	1,443	254	—	1,697	(1,282)	(202)	—	213
Long-term debt (5)	50,263	125	4	50,392	—	—	(4,890)	45,502
Long-term obligations to equity companies (6)	—	—	3,530	3,530	—	—	(277)	3,253
Other long-term financial liabilities (7)	—	—	964	964	—	—	44	1,008


	At December 31, 2019
	(millions of dollars)
	Fair Value
	Level 1	Level 2	Level 3	Total Gross Assets & Liabilities	Effect of Counterparty Netting	Effect of Collateral Netting	Difference in Carrying Value and Fair Value	Net Carrying Value
Assets
Derivative assets (1)	533	102	—	635	(463)	(70)	—	102
Advances to/receivables from equity companies (2)(6)	—	1,941	6,729	8,670	—	—	(128)	8,542
Other long-term financial assets (3)	1,145	—	974	2,119	—	—	44	2,163

Liabilities
Derivative liabilities (4)	568	70	—	638	(463)	(105)	—	70
Long-term debt (5)	25,652	134	3	25,789	—	—	(1,117)	24,672
Long-term obligations to equity companies (6)	—	—	4,245	4,245	—	—	(257)	3,988
Other long-term financial liabilities (7)	—	—	1,042	1,042	—	—	16	1,058

(1)Included in the Balance Sheet lines: Notes and accounts receivable - net and Other assets, including intangibles - net

(2)Included in the Balance Sheet line: Investments, advances and long-term receivables

(3)Included in the Balance Sheet lines: Investments, advances and long term receivables and Other assets, including intangibles - net

(4)Included in the Balance Sheet lines: Accounts payable and accrued liabilities and Other long-term obligations

(5)Excluding finance lease obligations

Schedule of Notional Amounts of Outstanding Derivative Positions

The net notional long/(short) position of derivative instruments at December 31, 2020, and December 31, 2019, was as follows:


	December 31,	December 31,
	2020	2019
	(millions)
Crude oil (barrels)	40	57
Petroleum products (barrels)	(46)	(38)
Natural gas (MMBTUs)	(500)	(165)

Derivative Instruments - Before-Tax Realized and Unrealized Gains / (Losses)

Realized and unrealized gains/(losses) on derivative instruments that were recognized in the Consolidated Statement of Income are included in the following lines on a before-tax basis:


	2020	2019	2018
	(millions of dollars)
Sales and other operating revenue	404	(412)	130
Crude oil and product purchases	(407)	179	(120)
Total	(3)	(233)	10

Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2020

Long-term Debt, Unclassified [Abstract]

Summarized Long-Term Debt

Summarized long-term debt at year-end 2020 and 2019 are shown in the table below:


	Average Rate (1)	Dec 31, 2020	Dec 31, 2019
		(millions of dollars)
Exxon Mobil Corporation (2)
2.222% notes due 2021		—	2,500
2.397% notes due 2022		1,150	1,150
1.902% notes due 2022		750	750
Floating-rate notes due 2022 (Issued 2015)	1.118%	500	500
Floating-rate notes due 2022 (Issued 2019)	1.189%	750	750
1.571% notes due 2023		2,750	—
2.726% notes due 2023		1,250	1,250
3.176% notes due 2024		1,000	1,000
2.019% notes due 2024		1,000	1,000
2.709% notes due 2025		1,750	1,750
2.992% notes due 2025		2,807	—
3.043% notes due 2026		2,500	2,500
2.275% notes due 2026		1,000	1,000
3.294% notes due 2027		1,000	—
2.440% notes due 2029		1,250	1,250
3.482% notes due 2030		2,000	—
2.610% notes due 2030		2,000	—
2.995% notes due 2039		750	750
4.227% notes due 2040		2,091	—
3.567% notes due 2045		1,000	1,000
4.114% notes due 2046		2,500	2,500
3.095% notes due 2049		1,500	1,500
4.327% notes due 2050		2,750	—
3.452% notes due 2051		2,750	—
Exxon Mobil Corporation - Euro-denominated
0.142% notes due 2024		1,841	—
0.524% notes due 2028		1,227	—
0.835% notes due 2032		1,227	—
1.408% notes due 2039		1,227	—
XTO Energy Inc. (3)
6.100% senior notes due 2036		192	193
6.750% senior notes due 2037		294	296
6.375% senior notes due 2038		227	229
Mobil Corporation
8.625% debentures due 2021		—	250

Industrial revenue bonds due 2022-2051	0.437%	2,461	2,461
Other U.S. dollar obligations		78	89
Other foreign currency obligations		61	64
Finance lease obligations	8.730%	1,680	1,670
Debt issuance costs		(131)	(60)
Total long-term debt		47,182	26,342

(1)Average effective interest rate for debt and average imputed interest rate for finance leases at December 31, 2020.

(2)Includes premiums of $148 million in 2020.

(3)Includes premiums of $87 million in 2020 and $92 million in 2019.

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21521-112644

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21538-112644

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

Incentive Program (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Summary Of Restricted Stock And Units Outstanding

The following tables summarize information about restricted stock and restricted stock units for the year ended December 31, 2020.


	2020
Restricted stock and units outstanding	Shares	Weighted Average Grant-Date Fair Value per Share
	(thousands)	(dollars)
Issued and outstanding at January 1	39,628	84.50
Awards issued in 2020	9,030	68.95
Vested	(8,990)	86.84
Forfeited	(83)	82.04
Issued and outstanding at December 31	39,585	80.43

Grant Value Of Restricted Stock Units


Value of restricted stock units	2020	2019	2018
Grant price (dollars)	41.15	68.77	77.66

Value at date of grant:	(millions of dollars)
Units settled in stock	325	559	620
Units settled in cash	32	55	61
Total value	357	614	681

Litigation And Other Contingencies (Tables)

12 Months Ended

Dec. 31, 2020

Loss Contingency [Abstract]

Schedule Of Guarantees


	December 31, 2020
	Equity Company Obligations (1)	Other Third-Party Obligations	Total
	(millions of dollars)
Guarantees
Debt-related	986	124	1,110
Other	745	4,944	5,689
Total	1,731	5,068	6,799

(1)ExxonMobil share.

Pension And Other Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2020

Retirement Benefits [Abstract]

Change In Benefit Obligation Of Pension And Other Postretirement Benefits


	Pension Benefits				Other Postretirement
	U.S.		Non-U.S.		Benefits
	2020	2019	2020	2019	2020	2019
	(percent)
Weighted-average assumptions used to determine benefit obligations at December 31
Discount rate	2.80	3.50	1.60	2.30	2.80	3.50
Long-term rate of compensation increase	5.50	5.75	4.20	4.80	5.50	5.75

	(millions of dollars)
Change in benefit obligation
Benefit obligation at January 1	20,959	18,174	29,918	25,378	8,113	7,471
Service cost	965	757	707	551	181	139
Interest cost	708	766	657	763	277	315
Actuarial loss/(gain) (1)	1,287	2,562	2,344	3,703	(66)	556
Benefits paid (2) (3)	(1,987)	(1,300)	(1,317)	(1,196)	(510)	(517)
Foreign exchange rate changes	—	—	1,375	391	23	25
Amendments, divestments and other	(270)	—	(58)	328	117	124
Benefit obligation at December 31	21,662	20,959	33,626	29,918	8,135	8,113
Accumulated benefit obligation at December 31	17,502	16,387	30,952	27,236	—	—

(1)Actuarial loss/(gain) primarily reflects changes in discount rates, partially offset by lower long-term rates of compensation.

(2)Benefit payments for funded and unfunded plans.

(3)For 2020 and 2019, other postretirement benefits paid are net of $16 million and $20 million of Medicare subsidy receipts, respectively.

Change In Plan Assets Of Pension And Other Postretirement Benefits


	Pension Benefits				Other Postretirement
	U.S.		Non-U.S.		Benefits
	2020	2019	2020	2019	2020	2019
	(millions of dollars)
Change in plan assets
Fair value at January 1	13,636	11,134	22,916	19,486	425	386
Actual return on plan assets	2,269	2,521	2,795	3,210	42	54
Foreign exchange rate changes	—	—	1,011	513	—	—
Company contribution	1,004	1,022	597	602	37	41
Benefits paid (1)	(1,609)	(1,041)	(992)	(883)	(58)	(56)
Other	—	—	(111)	(12)	—	—
Fair value at December 31	15,300	13,636	26,216	22,916	446	425

(1) Benefit payments for funded plans.

Summary Of Assets In Excess Of/(Less Than) Benefit Obligation


	Pension Benefits
	U.S.		Non-U.S.
	2020	2019	2020	2019
	(millions of dollars)
Assets in excess of/(less than) benefit obligation
Balance at December 31
Funded plans	(4,156)	(4,656)	(1,223)	(1,728)
Unfunded plans	(2,206)	(2,667)	(6,187)	(5,274)
Total	(6,362)	(7,323)	(7,410)	(7,002)

Amounts Recorded In Balance Sheet And Other Comprehensive Income


	Pension Benefits				Other Postretirement Benefits
	U.S.		Non-U.S.
	2020	2019	2020	2019	2020	2019
	(millions of dollars)
Assets in excess of/(less than) benefit obligation
Balance at December 31 (1)	(6,362)	(7,323)	(7,410)	(7,002)	(7,689)	(7,688)

Amounts recorded in the consolidated balance sheet consist of:
Other assets	—	—	1,931	1,151	—	—
Current liabilities	(377)	(242)	(273)	(267)	(327)	(351)
Postretirement benefits reserves	(5,985)	(7,081)	(9,068)	(7,886)	(7,362)	(7,337)
Total recorded	(6,362)	(7,323)	(7,410)	(7,002)	(7,689)	(7,688)

Amounts recorded in accumulated other comprehensive income consist of:
Net actuarial loss/(gain)	3,102	3,971	5,904	5,662	1,164	1,339
Prior service cost	(275)	1	208	360	(274)	(315)
Total recorded in accumulated other comprehensive income	2,827	3,972	6,112	6,022	890	1,024

(1) Fair value of assets less benefit obligation shown on the preceding page.

Schedule Of Assumptions, Components Of Benefit Cost And Amounts Recorded In Accumulated Other Comprehensive Income For Pension And Other Postretirement Benefits


	Pension Benefits						Other Postretirement Benefits
	U.S.			Non-U.S.
	2020	2019	2018	2020	2019	2018	2020	2019	2018
Weighted-average assumptions used to determine net periodic benefit cost for years ended December 31	(percent)
Discount rate	3.50	4.40	3.80	2.30	3.00	2.80	3.50	4.40	3.80
Long-term rate of return on funded assets	5.30	5.30	6.00	4.10	4.10	4.70	4.60	4.60	6.00
Long-term rate of compensation increase	5.75	5.75	5.75	4.80	4.30	4.30	5.75	5.75	5.75

Components of net periodic benefit cost	(millions of dollars)
Service cost	965	757	819	707	551	608	181	139	152
Interest cost	708	766	721	657	763	754	277	315	301
Expected return on plan assets	(703)	(568)	(727)	(897)	(777)	(951)	(18)	(15)	(23)
Amortization of actuarial loss/(gain)	310	305	362	416	306	409	95	55	116
Amortization of prior service cost	5	5	5	68	56	46	(42)	(42)	(40)
Net pension enhancement and curtailment/settlement cost	280	164	268	49	(98)	44	—	—	—
Net periodic benefit cost	1,565	1,429	1,448	1,000	801	910	493	452	506

Changes in amounts recorded in accumulated other comprehensive income:
Net actuarial loss/(gain)	(279)	609	479	446	1,268	(66)	(92)	517	(594)
Amortization of actuarial (loss)/gain	(590)	(469)	(630)	(442)	(208)	(453)	(95)	(55)	(116)
Prior service cost/(credit)	(271)	—	—	(82)	379	98	—	—	—
Amortization of prior service (cost)/credit	(5)	(5)	(5)	(68)	(56)	(46)	42	42	40
Foreign exchange rate changes	—	—	—	236	19	(356)	11	—	(8)
Total recorded in other comprehensive income	(1,145)	135	(156)	90	1,402	(823)	(134)	504	(678)
Total recorded in net periodic benefit cost and other comprehensive income, before tax	420	1,564	1,292	1,090	2,203	87	359	956	(172)

Summary Of Change In Accumulated Other Comprehensive Income

A summary of the change in accumulated other comprehensive income is shown in the table below:


	Total Pension and Other Postretirement Benefits
	2020	2019	2018
	(millions of dollars)
(Charge)/credit to other comprehensive income, before tax
U.S. pension	1,145	(135)	156
Non-U.S. pension	(90)	(1,402)	823
Other postretirement benefits	134	(504)	678
Total (charge)/credit to other comprehensive income, before tax	1,189	(2,041)	1,657
(Charge)/credit to income tax (see Note 4)	(153)	550	(470)
(Charge)/credit to investment in equity companies	(110)	(19)	24
(Charge)/credit to other comprehensive income including noncontrolling interests, after tax	926	(1,510)	1,211
Charge/(credit) to equity of noncontrolling interests	30	146	(114)
(Charge)/credit to other comprehensive income attributable to ExxonMobil	956	(1,364)	1,097

Fair Value Of The Benefit Plan Assets (Pension)

The 2020 fair value of the benefit plan assets, including the level within the fair value hierarchy, is shown in the tables below:


	U.S. Pension						Non- U.S. Pension
	Fair Value Measurement at December 31, 2020, Using:						Fair Value Measurement at December 31, 2020, Using:
	Level 1	Level 2		Level 3	Net Asset Value	Total	Level 1		Level 2		Level 3	Net Asset Value	Total
	(millions of dollars)
Asset category:
Equity securities
U.S.	—	—		—	2,323	2,323	—		—		—	4,177	4,177
Non-U.S.	—	—		—	1,703	1,703	89	(1)	—		—	3,285	3,374
Private equity	—	—		—	548	548	—		—		—	530	530
Debt securities
Corporate	—	5,146	(2)	—	1	5,147	—		138	(2)	—	5,212	5,350
Government	—	5,261	(2)	—	2	5,263	250	(3)	116	(2)	—	11,993	12,359
Asset-backed	—	—		—	1	1	—		24	(2)	—	239	263
Cash	—	—		—	308	308	69		21	(4)	—	50	140
Total at fair value	—	10,407		—	4,886	15,293	408		299		—	25,486	26,193
Insurance contracts at contract value						7							23
Total plan assets						15,300							26,216

(1)For non-U.S. equity securities held in separate accounts, fair value is based on observable quoted prices on active exchanges.

(2)For corporate, government and asset-backed debt securities, fair value is based on observable inputs of comparable market transactions.

(3)For government debt securities that are traded on active exchanges, fair value is based on observable quoted prices.

(4)For cash balances that are subject to withdrawal penalties or other adjustments, the fair value is treated as a Level 2 input.

The 2019 fair value of the benefit plan assets, including the level within the fair value hierarchy, is shown in the tables below:


	U.S. Pension						Non-U.S. Pension
	Fair Value Measurement at December 31, 2019, Using:						Fair Value Measurement at December 31, 2019, Using:
	Level 1	Level 2		Level 3	Net Asset Value	Total		Level 1		Level 2		Level 3	Net Asset Value	Total
	(millions of dollars)
Asset category:
Equity securities
U.S.	—	—		—	1,960	1,960		—		—		—	3,436	3,436
Non-U.S.	—	—		—	1,656	1,656		70	(1)	—		—	3,015	3,085
Private equity	—	—		—	499	499		—		—		—	489	489
Debt securities
Corporate	—	4,932	(2)	—	1	4,933		—		129	(2)	—	4,486	4,615
Government	—	4,470	(2)	—	2	4,472		280	(3)	139	(2)	—	10,511	10,930
Asset-backed	—	—		—	1	1		—		21	(2)	—	212	233
Cash	—	—		—	107	107		33		12	(4)	—	61	106
Total at fair value	—	9,402		—	4,226	13,628		383		301		—	22,210	22,894
Insurance contracts at contract value						8								22
Total plan assets						13,636								22,916

(1)For non-U.S. equity securities held in separate accounts, fair value is based on observable quoted prices on active exchanges.

(2)For corporate, government and asset-backed debt securities, fair value is based on observable inputs of comparable market transactions.

(3)For government debt securities that are traded on active exchanges, fair value is based on observable quoted prices.

(4)For cash balances that are subject to withdrawal penalties or other adjustments, the fair value is treated as a Level 2 input.

Fair Value Of The Benefit Plan Assets (Other Postretirement)


	Other Postretirement
	Fair Value Measurement at December 31, 2020, Using:
	Level 1		Level 2		Level 3	Net Asset Value	Total
	(millions of dollars)
Asset category:
Equity securities
U.S.	88	(1)	—		—	—	88
Non-U.S.	48	(1)	—		—	—	48
Debt securities
Corporate	—		103	(2)	—	—	103
Government	—		204	(2)	—	—	204
Asset-backed	—		—		—	—	—
Cash	—		—		—	3	3
Total at fair value	136		307		—	3	446

(1)For equity securities held in separate accounts, fair value is based on observable quoted prices on active exchanges.

(2)For corporate, government and asset-backed debt securities, fair value is based on observable inputs of comparable market transactions.


	Other Postretirement
	Fair Value Measurement at December 31, 2019, Using:
	Level 1	Level 2		Level 3	Net Asset Value	Total
	(millions of dollars)
Asset category:
Equity securities
U.S.	—	—		—	81	81
Non-U.S.	—	—		—	49	49
Debt securities
Corporate	—	92	(1)	—	—	92
Government	—	200	(1)	—	—	200
Asset-backed	—	—		—	—	—
Cash	—	—		—	3	3
Total at fair value	—	292		—	133	425

(1)For corporate, government and asset-backed debt securities, fair value is based on observable inputs of comparable market transactions.

Pension Plans With Accumulated Benefit Obligation In Excess Of Plan Assets

A summary of pension plans with an accumulated benefit obligation and projected benefit obligation in excess of plan assets is shown in the table below:


	Pension Benefits
	U.S.		Non-U.S.
	2020	2019	2020	2019
	(millions of dollars)
For funded pension plans with an accumulated benefit obligation
in excess of plan assets:
Accumulated benefit obligation	16,129	14,940	4,602	3,026
Fair value of plan assets	15,300	13,636	2,652	1,381

For funded pension plans with a projected benefit obligation in excess of plan assets:
Projected benefit obligation	19,456	18,292	13,836	12,496
Fair value of plan assets	15,300	13,636	10,681	9,616

For unfunded pension plans:
Projected benefit obligation	2,206	2,667	6,187	5,274
Accumulated benefit obligation	1,373	1,447	5,469	4,629

Expected Contributions and Benefit Payments for Pension Benefits And Other Postretirement Benefits


	Pension Benefits		Other Postretirement Benefits
	U.S.	Non-U.S.	Gross	Medicare Subsidy Receipt
	(millions of dollars)
Contributions expected in 2021	865	395	—	—
Benefit payments expected in:
2021	2,434	1,310	424	22
2022	1,079	1,193	426	23
2023	1,105	1,214	420	25
2024	1,124	1,240	418	26
2025	1,142	1,186	415	27
2026 - 2030	5,971	6,274	2,058	143

Disclosures About Segments And Related Information (Tables)

12 Months Ended

Dec. 31, 2020

Segment Reporting, Measurement Disclosures [Abstract]

Disclosures About Segments And Related Information


	Upstream		Downstream		Chemical		Corporate and	Corporate
	U.S.	Non-U.S.	U.S.	Non-U.S.	U.S.	Non-U.S.	Financing	Total
	(millions of dollars)
As of December 31, 2020
Earnings (Loss) after income tax	(19,385)	(645)	(852)	(225)	1,277	686	(3,296)	(22,440)
Effect of asset impairments - noncash	(17,138)	(2,287)	(15)	(609)	(100)	(69)	(35)	(20,253)
Earnings of equity companies included above	(559)	2,101	134	(190)	(21)	651	(384)	1,732
Sales and other operating revenue	5,876	8,673	48,256	92,640	8,529	14,562	38	178,574
Intersegment revenue	8,508	19,642	12,258	15,162	6,099	3,881	221	—
Depreciation and depletion expense	28,627	12,723	716	1,672	685	694	892	46,009
Interest revenue	—	—	—	—	—	—	49	49
Interest expense	52	93	1	21	—	—	991	1,158
Income tax expense (benefit)	(5,958)	742	(324)	393	440	272	(1,197)	(5,632)
Additions to property, plant and equipment	5,726	4,418	2,983	1,731	1,221	592	671	17,342
Investments in equity companies	4,792	18,135	352	879	2,543	3,514	(443)	29,772
Total assets	71,287	144,730	23,754	34,848	17,839	20,220	20,072	332,750

As of December 31, 2019
Earnings after income tax	536	13,906	1,717	606	206	386	(3,017)	14,340
Earnings of equity companies included above	282	4,534	196	19	(4)	818	(404)	5,441
Sales and other operating revenue	9,364	13,779	70,523	134,460	9,723	17,693	41	255,583
Intersegment revenue	10,893	30,864	22,416	24,775	7,864	5,905	224	—
Depreciation and depletion expense	6,162	9,305	674	832	555	621	849	18,998
Interest revenue	—	—	—	—	—	—	84	84
Interest expense	54	34	1	9	—	1	731	830
Income tax expense (benefit)	(151)	5,509	465	361	58	305	(1,265)	5,282
Additions to property, plant and equipment	10,404	7,347	2,685	1,777	1,344	589	758	24,904
Investments in equity companies	5,313	17,736	319	1,062	1,835	3,335	(309)	29,291
Total assets	95,750	151,181	23,442	37,133	16,544	20,376	18,171	362,597

As of December 31, 2018
Earnings after income tax	1,739	12,340	2,962	3,048	1,642	1,709	(2,600)	20,840
Earnings of equity companies included above	608	5,816	156	(6)	48	1,113	(380)	7,355
Sales and other operating revenue	10,359	15,158	74,327	147,007	12,239	20,204	38	279,332
Intersegment revenue	8,683	29,659	21,954	29,888	9,044	7,217	205	—
Depreciation and depletion expense	6,024	9,257	684	890	405	606	879	18,745
Interest revenue	—	—	—	—	—	—	64	64
Interest expense	77	31	2	12	—	1	643	766
Income tax expense (benefit)	104	8,149	946	1,008	566	245	(1,486)	9,532
Additions to property, plant and equipment	7,119	7,974	1,152	1,595	1,146	348	717	20,051
Investments in equity companies	4,566	16,337	293	1,162	870	3,431	(277)	26,382
Total assets	90,310	148,914	17,898	34,024	14,904	21,131	19,015	346,196

Geographic Sales And Other Operating Revenue


Sales and other operating revenue	2020	2019	2018
	(millions of dollars)
United States	62,663	89,612	96,930
Non-U.S.	115,911	165,971	182,402
Total	178,574	255,583	279,332

Significant non-U.S. revenue sources include: (1)
Canada	13,093	19,735	22,672
United Kingdom	11,055	17,479	18,702
Singapore	9,442	12,128	13,689
France	8,676	12,740	13,637
Italy	7,091	10,459	13,396
Belgium	6,231	11,644	15,664
Australia	5,839	7,941	8,780

(1)Revenue is determined by primary country of operations. Excludes certain sales and other operating revenues in Non-U.S. operations where attribution to a specific country is not practicable.

Schedule Of Long-Lived Assets By Geographic Regions


	December 31,
Long-lived assets	2020	2019	2018
	(millions of dollars)
United States	94,732	114,372	108,147
Non-U.S.	132,821	138,646	138,954
Total	227,553	253,018	247,101

Significant non-U.S. long-lived assets include:
Canada	36,232	39,130	37,433
Australia	14,792	13,933	14,548
Singapore	12,129	11,645	11,148
Kazakhstan	8,882	9,315	9,726
Papua New Guinea	7,803	8,057	8,269
Nigeria	6,345	7,640	8,421
United Arab Emirates	5,381	5,262	4,859
Russia	4,616	5,135	5,456
Angola	4,405	5,784	7,021

Income And Other Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Income And Other Taxes [Abstract]

Schedule Of Income And Other Taxes


	2020			2019			2018
	U.S.	Non-U.S.	Total	U.S.	Non-U.S.	Total	U.S.	Non-U.S.	Total
				(millions of dollars)
Income tax expense (benefit)
Federal and non-U.S.
Current	262	2,908	3,170	(121)	6,171	6,050	459	9,001	9,460
Deferred - net	(6,045)	(2,007)	(8,052)	(255)	(420)	(675)	518	(614)	(96)
U.S. tax on non-U.S. operations	13	—	13	89	—	89	42	—	42
Total federal and non-U.S.	(5,770)	901	(4,869)	(287)	5,751	5,464	1,019	8,387	9,406
State	(763)	—	(763)	(182)	—	(182)	126	—	126
Total income tax expense (benefit)	(6,533)	901	(5,632)	(469)	5,751	5,282	1,145	8,387	9,532
All other taxes and duties
Other taxes and duties	3,108	23,014	26,122	3,566	26,959	30,525	3,498	29,165	32,663
Included in production and manufacturing expenses	1,148	663	1,811	1,385	811	2,196	1,245	857	2,102
Included in SG&A expenses	164	328	492	160	305	465	153	312	465
Total other taxes and duties	4,420	24,005	28,425	5,111	28,075	33,186	4,896	30,334	35,230
Total	(2,113)	24,906	22,793	4,642	33,826	38,468	6,041	38,721	44,762

Reconciliation Between Income Tax Expense And A Theoretical U.S. Tax

The reconciliation between income tax expense (credit) and a theoretical U.S. tax computed by applying a rate of 21 percent for 2020, 2019 and 2018 is as follows:


	2020		2019		2018
	(millions of dollars)
Income (Loss) before income taxes
United States	(27,704)		(53)		5,200
Non-U.S.	(1,179)		20,109		25,753
Total	(28,883)		20,056		30,953
Theoretical tax	(6,065)		4,212		6,500
Effect of equity method of accounting	(364)		(1,143)		(1,545)
Non-U.S. taxes in excess of/(less than) theoretical U.S. tax (1)(2)	1,606		2,573		4,626
State taxes, net of federal tax benefit (1)	(603)		(144)		100
Enactment-date effects of U.S. tax reform	—		—		(291)
Other	(206)		(216)		142
Total income tax expense (credit)	(5,632)		5,282		9,532

Effective tax rate calculation
Income tax expense (credit)	(5,632)		5,282		9,532
ExxonMobil share of equity company income taxes	861		2,490		3,142
Total income tax expense (credit)	(4,771)		7,772		12,674
Net income (loss) including noncontrolling interests	(23,251)		14,774		21,421
Total income (loss) before taxes	(28,022)		22,546		34,095
Effective income tax rate	17	%	34	%	37	%

(1)2020 includes the impact of an increase in valuation allowance of $647 million in non-U.S. and $115 million in U.S. state jurisdictions.

Deferred Tax Liabilities/(Assets)

Deferred tax liabilities/(assets) are comprised of the following at December 31:


Tax effects of temporary differences for:	2020	2019
	(millions of dollars)
Property, plant and equipment	28,778	36,029
Other liabilities	6,427	7,653
Total deferred tax liabilities	35,205	43,682

Pension and other postretirement benefits	(4,703)	(4,712)
Asset retirement obligations	(3,150)	(3,403)
Tax loss carryforwards	(8,982)	(7,404)
Other assets	(7,095)	(7,735)
Total deferred tax assets	(23,930)	(23,254)

Asset valuation allowances	2,731	1,924
Net deferred tax liabilities	14,006	22,352

Deferred Income Tax (Assets) And Liabilities By Balance Sheet Classification


Balance sheet classification	2020	2019
	(millions of dollars)
Other assets, including intangibles, net	(4,159)	(3,268)
Deferred income tax liabilities	18,165	25,620
Net deferred tax liabilities	14,006	22,352

Unrecognized Tax Benefits

The following table summarizes the movement in unrecognized tax benefits:


Gross unrecognized tax benefits	2020	2019	2018
	(millions of dollars)
Balance at January 1	8,844	9,174	8,783
Additions based on current year's tax positions	253	287	375
Additions for prior years' tax positions	218	120	240
Reductions for prior years' tax positions	(201)	(97)	(125)
Reductions due to lapse of the statute of limitations	(237)	(279)	(5)
Settlements with tax authorities	(113)	(538)	(68)
Foreign exchange effects/other	—	177	(26)
Balance at December 31	8,764	8,844	9,174

Remaining Tax Years Subject To Examination By Major Tax Jurisdiction

The following table summarizes the tax years that remain subject to examination by major tax jurisdiction:


Country of Operation	Open Tax Years
Abu Dhabi	2018	—	2020
Angola	2018	—	2020
Australia	2010	—	2020
Belgium	2017	—	2020
Canada	2001	—	2020
Equatorial Guinea	2007	—	2020
Indonesia	2007	—	2020
Iraq	2015	—	2020
Malaysia	2011	—	2020
Nigeria	2006	—	2020
Norway	2010	—	2020
Papua New Guinea	2008	—	2020
Russia	2018	—	2020
United Kingdom	2015	—	2020
United States	2006	—	2020

Restructuring Activities (Tables)

12 Months Ended

Dec. 31, 2020

Restructuring and Related Activities [Abstract]

Summary of Reserves and Charges

The following table summarizes the reserves and charges related to the workforce reduction programs, which are recorded in “Accounts payable and accrued liabilities.”


			2020
			(millions of dollars)
Balance at January 1			—
Additions/adjustments			450
Payments made			(47)
Balance at December 31			403

Accounting Changes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2018
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Cumulative effect of accounting change	$ (94)	$ 47
ExxonMobil Share Of Earnings Reinvested [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Cumulative effect of accounting change	$ (93)	$ 71

Accounting Changes (CECL) (Details) $ in Millions	12 Months Ended
Accounting Changes (CECL) (Details) $ in Millions	Dec. 31, 2020 USD ($)
Liabilities for Off-Balance Sheet Assets [Roll Forward]
Balance at December 31, 2019, Off-Balance Sheet Assets	$ 0
Cumulative effect of accounting change, Off-Balance Sheet Assets	12
Current period provision, Off-Balance Sheet Assets	(1)
Other, Off-Balance Sheet Assets	0
Balance at December 31, 2020, Off-Balance Sheet Assets	11
Accounts And Financing Receivable And Off Balance Sheet Credit Liability [Roll Forward]
Balance at December 31, 2019, Total	503
Cumulative effect of accounting change, Total	109
Current period provision, Total	14
Write-offs charged against the allowance, Total	(5)
Other, Total	2
Balance at December 31, 2020, Total	623
Trade Accounts Receivable [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019, Trade and Other	34
Cumulative effect of accounting change, Trade and Other	52
Current period provision, Trade and Other	9
Write-offs charged against the allowance, Trade and Other	(2)
Other, Trade and Other	2
Balance at December 31, 2020, Trade and Other	95
Accounts And Financing Receivable And Off Balance Sheet Credit Liability [Roll Forward]
Accounts Receivable, after Allowance for Credit Loss	16,250
Notes And Accounts Receivable Other [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019, Trade and Other	56
Cumulative effect of accounting change, Trade and Other	6
Current period provision, Trade and Other	15
Write-offs charged against the allowance, Trade and Other	(3)
Other, Trade and Other	(3)
Balance at December 31, 2020, Trade and Other	71
Accounts And Financing Receivable And Off Balance Sheet Credit Liability [Roll Forward]
Accounts Receivable, after Allowance for Credit Loss	1,962
Advances And Long-Term Receivables [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019, Advances and Long-Term Receivables	413
Cumulative effect of accounting change, Advances and Long-Term Receivables	39
Current period provision, Advances and Long-Term Receivables	(9)
Write-offs charged against the allowance, Advances and Long-Term Receivables	0
Other, Advances and Long-Term Receivables	3
Balance at December 31, 2020, Advances and Long-Term Receivables	446
Accounts And Financing Receivable And Off Balance Sheet Credit Liability [Roll Forward]
Financing Receivable, after Allowance for Credit Loss	$ 9,447

Miscellaneous Financial Information (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Research and development expense	$ 1,016	$ 1,214	$ 1,116
Foreign currency transaction gain/(loss), before tax	(24)	(104)	(138)
Gains/(losses) on combined effects of LIFO inventory accumulations and draw-downs	41	523	$ 107
Aggregate replacement cost of inventories estimated to exceed LIFO carrying values	5,400	$ 9,700
Before-tax goodwill impairment charges	$ 611

Miscellaneous Financial Information (Crude Oil, Products And Merchandise) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Crude oil	$ 5,354	$ 5,111
Petroleum products	5,138	5,281
Chemical products	3,023	3,240
Gas/other	654	378
Total	$ 14,169	$ 14,010

Other Comprehensive Income Information (Schedule of Accumulated Other Comprehensive Income Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Comprehensive Income Foreign Currency Transaction and Translation Adjustment Net Of Tax Period Increase Decrease [Abstract]
Current period change excluding amounts reclassified from accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment	$ 1,916	$ 1,735	$ (5,077)
Amounts reclassified from accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment	14	0	196
Other Comprehensive Income Defined Benefit Plans, Net Of Tax Period Increase Decrease [Abstract]
Current period change excluding amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment	30	(2,092)	280
Amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment	896	582	931
Other Comprehensive Income Loss Net Of Tax Period Change [Abstract]
Beginning Balance, Total	(19,493)
Ending Balance, Total	(16,705)	(19,493)
Exxon Mobil Corporation Share After Noncontrolling Interest [Member]
Other Comprehensive Income Foreign Currency Transaction and Translation Adjustment Net Of Tax Period Increase Decrease [Abstract]
Beginning Balance, Cumulative Foreign Exchange Translation Adjustment	(12,446)	(13,881)	(9,482)
Current period change excluding amounts reclassified from accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment	1,818	1,435	(4,595)
Amounts reclassified from accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment	14	0	196
Total change in accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment	1,832	1,435	(4,399)
Ending Balance, Cumulative Foreign Exchange Translation Adjustment	(10,614)	(12,446)	(13,881)
Net investment hedge gain/(loss), net of taxes	(355)
Other Comprehensive Income Defined Benefit Plans, Net Of Tax Period Increase Decrease [Abstract]
Beginning Balance, Postretirement Benefits Reserves Adjustment	(7,047)	(5,683)	(6,780)
Current period change excluding amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment	95	(1,927)	201
Amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment	861	563	896
Total change in accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment	956	(1,364)	1,097
Ending Balance, Postretirement Benefits Reserves Adjustment	(6,091)	(7,047)	(5,683)
Other Comprehensive Income Loss Net Of Tax Period Change [Abstract]
Beginning Balance, Total	(19,493)	(19,564)	(16,262)
Current period change excluding amounts reclassified from accumulated other comprehensive income, Total	1,913	(492)	(4,394)
Amounts reclassified from accumulated other comprehensive income, Total	875	563	1,092
Total change in accumulated other comprehensive income	2,788	71	(3,302)
Ending Balance, Total	$ (16,705)	$ (19,493)	$ (19,564)

Other Comprehensive Income Information (Amounts Reclassified Out Of Acc Other Comp Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Comprehensive Income Information Before Tax [Abstract]
Foreign exchange translation gain/(loss) included in net income (Statement of Income line: Other income)	$ (14)	$ 0	$ (196)
Amortization and settlement of postretirement benefits reserves adjustment included in net periodic benefit costs (Statement of Income line: Non-service pension and postretirement benefit expense)	$ (1,158)	$ (751)	$ (1,208)

Other Comprehensive Income Information (Schedule Of Income Tax (Expense)/Credit For Components Of Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Comprehensive Income Information Tax [Abstract]
Foreign exchange translation adjustment	$ 118	$ 88	$ 32
Postretirement benefits reserves adjustment (excluding amortization)	109	719	(193)
Amortization and settlement of postretirement benefits reserves adjustment included in net periodic benefit costs	(262)	(169)	(277)
Total	$ (35)	$ 638	$ (438)

Cash Flow Information (Cash Payments For Interest And Income Taxes) (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Maturity greater than three months [Member]
Net cash flow from issuance/(repayment) of commercial paper	$ 8,400	$ 4,600	$ 275
Proceeds from issuance of commercial paper	35,400	18,900	4,000
Repayments of commercial paper	$ 27,000	14,300	$ 3,800
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| Nonoperated Upstream Assets In Norway [Member]
Sales price of non-operated upstream assets		4,500
After tax gain on sale of non-operated upstream assets		3,700
Proceeds from Divestiture of Businesses		$ 3,100

Cash Flow Information (Cash Payments For Interest And Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Supplemental Cash Flow Information [Abstract]
Income taxes paid	$ 2,428	$ 7,018	$ 9,294
Cash interest paid - Included in cash flows from operating activities	786	560	303
Cash interest paid - capitalized, included in cash flows from investing activities	665	731	652
Total cash interest paid	$ 1,451	$ 1,291	$ 955

Additional Working Capital Information (Narrative) (Details) - USD ($) $ in Billions	Dec. 31, 2020	Dec. 31, 2019
Line of Credit Facility [Line Items]
Weighted-average interest rate on short-term borrowings outstanding	0.20%	1.70%
Short Term Financing [Member]
Line of Credit Facility [Line Items]
Unused credit lines	$ 11.3

Additional Working Capital Information (Schedule Of Notes, Accounts Receivable And Payable, Loans Payable, Accrued Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Notes and Accounts Receivable [Abstract]
Trade notes and accounts receivable, less reserves of $96 million and $34 million	$ 16,339	$ 21,100
Other notes and accounts receivable, less reserves of $378 million and $371 million	4,242	5,866
Total notes and accounts receivable	20,581	26,966
Trade notes and accounts receivable, reserves	96	34
Other notes and accounts receivable, reserves	378	371
Notes and Loans Payable [Abstract]
Bank loans	222	316
Commercial paper	17,306	18,561
Long-term debt due within one year	2,930	1,701
Total notes and loans payable	20,458	20,578
Accounts Payable and Accrued Liabilities Current [Abstract]
Trade payables	17,499	24,694
Payables to equity companies	6,476	6,825
Accrued taxes other than income taxes	3,408	3,301
Other accounts payable and accrued liabilities	7,838	7,011
Total accounts payable and accrued liabilities	$ 35,221	$ 41,831

Equity Company Information (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Share of equity company revenues from sales to consolidated companies	11.00%	13.00%	14.00%
Upstream [Member] \| U.S. [Member]
Schedule of Equity Method Investments [Line Items]
Impairment related to equity method investments	$ 600

Equity Company Information (Schedule Of Equity Company Financial Summary) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Investments (Companies carried at equity in underlying assets)	$ 29,772	$ 29,291	$ 26,382
Total Equity Company Including All Owners [Member]
Schedule of Equity Method Investments [Line Items]
Total revenues	69,954	102,365	112,938
Income before income taxes	12,743	29,424	37,203
Income taxes	4,333	9,725	11,568
Income from equity affiliates	8,410	19,699	25,635
Current assets	33,419	36,035	38,670
Long-term assets	150,358	143,321	128,830
Total assets	183,777	179,356	167,500
Current liabilities	18,827	24,583	27,324
Long-term liabilities	66,053	61,022	56,913
Investments (Companies carried at equity in underlying assets)	98,897	93,751	83,263
Exxon Mobil Corporation Share After Noncontrolling Interest [Member]
Schedule of Equity Method Investments [Line Items]
Total revenues	21,282	31,240	34,539
Income before income taxes	2,830	7,927	10,482
Income taxes	870	2,500	3,151
Income from equity affiliates	1,960	5,427	7,331
Current assets	11,969	12,661	13,394
Long-term assets	41,457	40,001	35,970
Total assets	53,426	52,662	49,364
Current liabilities	5,245	6,939	7,606
Long-term liabilities	19,927	18,158	17,109
Investments (Companies carried at equity in underlying assets)	$ 28,254	$ 27,565	$ 24,649

Equity Company Information (Schedule Of The Corporation's Percentage Ownership Interest) (Details)	Dec. 31, 2020
Upstream [Member] \| Aera Energy LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	48.00%
Upstream [Member] \| Barzan Gas Company Limited [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	7.00%
Upstream [Member] \| BEB Erdgas und Erdoel GmbH & Co. KG [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Upstream [Member] \| Cameroon Oil Transportation Company S.A. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	41.00%
Upstream [Member] \| Caspian Pipeline Consortium - Kazakhstan [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	8.00%
Upstream [Member] \| Coral FLNG, S.A. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	25.00%
Upstream [Member] \| Cross Timbers Energy, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Upstream [Member] \| Golden Pass LNG Terminal LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	30.00%
Upstream [Member] \| Golden Pass Pipeline LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	30.00%
Upstream [Member] \| Marine Well Containment Company LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	10.00%
Upstream [Member] \| Mozambique Rovuma Venture, S.p.A. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	36.00%
Upstream [Member] \| Nederlandse Aardolie Maatschappij B.V. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Upstream [Member] \| Papua New Guinea Liquefied Natural Gas Global Company LDC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	33.00%
Upstream [Member] \| Permian Highway Pipeline LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	20.00%
Upstream [Member] \| Qatar Liquefied Gas Company Limited [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	10.00%
Upstream [Member] \| Qatar Liquefied Gas Company Limited (2) [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	24.00%
Upstream [Member] \| Ras Laffan Liquefied Natural Gas Company Limited [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	25.00%
Upstream [Member] \| Ras Laffan Liquefied Natural Gas Company Limited (II) [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	31.00%
Upstream [Member] \| Ras Laffan Liquefied Natural Gas Company Limited (3) [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	30.00%
Upstream [Member] \| South Hook LNG Terminal Company Limited [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	24.00%
Upstream [Member] \| Tengizchevroil, LLP [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	25.00%
Upstream [Member] \| Terminale GNL Adriatico S.r.l. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	71.00%
Downstream [Member] \| Alberta Products Pipe Line Ltd. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	45.00%
Downstream [Member] \| Fujian Refining & Petrochemical Co. Ltd. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	25.00%
Downstream [Member] \| Permian Express Partners LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	12.00%
Downstream [Member] \| Saudi Aramco Mobil Refinery Company Ltd. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Chemical [Member] \| Al-Jubail Petrochemical Company [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Chemical [Member] \| Gulf Coast Growth Ventures LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Chemical [Member] \| Saudi Yanbu Petrochemical Co. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%

Investments, Advances And Long-Term Receivables (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Long-term Investments and Receivables, Net [Abstract]
Investments	$ 29,772	$ 29,291	$ 26,382
Advances, net of allowances of $31 million in 2020	8,812	8,542
Total equity method company investments and advances	38,584	37,833
Equity securities carried at fair value and other investments at adjusted cost basis	143	190
Long-term receivables and miscellaneous, net of reserves of $6,115 million and $5,643 million	4,788	5,141
Total	43,515	43,164
Reserves for long-term receivables and miscellaneous investments	6,115	$ 5,643
Advances, allowances	$ 31

Property, Plant And Equipment And Asset Retirement Obligations (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Asset impairment charges, before-tax		$ 100	$ 700
Accumulated depreciation and depletion	$ 277,769	233,684
Interest capitalized	665	731	$ 652
Long-term asset retirement obligations	$ 10,558	$ 10,279
Measurement Input, Discount Rate [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Discounted cash flow discount rate	6.00%
Measurement Input, Discount Rate [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Discounted cash flow discount rate	8.00%
Upstream [Member]
Property, Plant and Equipment [Line Items]
Oil and gas properties impairment charges, before-tax	$ 24,400
Other asset impairment charges, before-tax	900
Downstream [Member]
Property, Plant and Equipment [Line Items]
Other asset impairment charges, before-tax	500
Chemical [Member]
Property, Plant and Equipment [Line Items]
Other asset impairment charges, before-tax	$ 100

Property, Plant And Equipment And Asset Retirement Obligations (Property, Plant And Equipment) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment, cost	$ 505,322	$ 486,702
Property, plant and equipment, net	227,553	253,018	$ 247,101
Upstream [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, cost	386,614	376,041
Property, plant and equipment, net	167,472	196,767
Downstream [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, cost	57,922	52,527
Property, plant and equipment, net	27,716	24,506
Chemical [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, cost	42,868	40,788
Property, plant and equipment, net	21,924	21,260
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, cost	17,918	17,346
Property, plant and equipment, net	$ 10,441	$ 10,485

Property, Plant And Equipment And Asset Retirement Obligations (Asset Retirement Obligations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant And Equipment And Asset Retirement Obligations [Abstract]
Balance at January 1	$ 11,280	$ 12,103	$ 12,705
Accretion expense and other provisions	584	649	681
Reduction due to property sales	(77)	(1,085)	(333)
Payments made	(669)	(827)	(600)
Liabilities incurred	26	89	46
Foreign currency translation	239	84	(481)
Revisions	(136)	267	85
Balance at December 31	$ 11,247	$ 11,280	$ 12,103

Accounting For Suspended Exploratory Well Costs (Narrative) (Details) $ in Millions	Dec. 31, 2020 USD ($) Projects	Dec. 31, 2019 USD ($) Projects	Dec. 31, 2018 USD ($) Projects	Dec. 31, 2017 USD ($)
Exploratory Wells Drilled [Line Items]
Number of projects that have exploratory well costs capitalized for a period greater than one year	34	46	52
Number of projects that have drilling in the preceding twelve months or exploratory activity planned in the next two years as of December 31, 2020	13
Number of projects with completed exploratory activity progressing toward development as of December 31, 2020	21
Capitalized exploratory well costs \| $	$ 4,382	$ 4,613	$ 4,160	$ 3,700
21 Projects [Member]
Exploratory Wells Drilled [Line Items]
Capitalized exploratory well costs \| $	$ 3,181

Accounting For Suspended Exploratory Well Costs (Change In Capitalized Suspended Exploratory Well Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Capitalized Exploratory Well Costs [Abstract]
Balance beginning at January 1	$ 4,613	$ 4,160	$ 3,700
Additions pending the determination of proved reserves	208	532	564
Charged to expense	(318)	(46)	(7)
Reclassifications to wells, facilities and equipment based on the determination of proved reserves	(174)	(37)	(48)
Divestments/Other	53	4	(49)
Ending balance at December 31	4,382	4,613	4,160
Ending balance attributed to equity companies included above	$ 306	$ 306	$ 306

Accounting For Suspended Exploratory Well Costs (Schedule Of Period End Capitalized Suspended Exploratory Well Costs) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized for a period of one year or less	$ 208	$ 532	$ 564
Capitalized for a period greater than one year - subtotal	4,174	4,081	3,596
Capitalized suspended exploratory well costs, total	4,382	4,613	4,160	$ 3,700
Capitalized For A Period Of Between One And Five Years [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized for a period greater than one year - subtotal	1,828	2,206	2,028
Capitalized For A Period Of Between Five And Ten Years [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized for a period greater than one year - subtotal	1,932	1,411	1,150
Capitalized For A Period Of Greater Than Ten Years [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized for a period greater than one year - subtotal	$ 414	$ 464	$ 418

Accounting For Suspended Exploratory Well Costs (Schedule Of Number Of Projects With Suspended Exploratory Well Costs) (Details) - Projects	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Capitalized Exploratory Well Costs [Abstract]
Number of projects that only have exploratory well costs capitalized for a period of one year or less	3	4	6
Number of projects that have exploratory well costs capitalized for a period greater than one year	34	46	52
Total	37	50	58

Leases (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Leases (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2020
Lessee Lease Description [Line Items]
Rental cost	$ 2,715
Operating Lease [Member]
Lessee Lease Description [Line Items]
Additional undiscounted commitments for leases not yet commenced		$ 445
Finance Lease [Member]
Lessee Lease Description [Line Items]
Additional undiscounted commitments for leases not yet commenced		$ 4,109

Leases (Lease Cost) (Details) - USD ($) $ in Millions	12 Months Ended
Leases (Lease Cost) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Operating Lease [Member]
Operating Leased Assets [Line Items]
Operating lease cost	$ 1,553	$ 1,434
Short-term and other (net of sublease rental income)	1,613	2,042
Total	3,166	3,476
Drilling Rigs and Related Equipment [Member]
Operating Leased Assets [Line Items]
Operating lease cost	297	238
Short-term and other (net of sublease rental income)	530	926
Total	827	1,164
Other [Member]
Operating Leased Assets [Line Items]
Operating lease cost	1,256	1,196
Short-term and other (net of sublease rental income)	1,083	1,116
Total	2,339	2,312
Finance Lease [Member]
Operating Leased Assets [Line Items]
Amortization of right of use assets	143	121
Interest on lease liabilities	169	133
Total	$ 312	$ 254

Leases (Right of Use) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Operating Lease [Member]
Lessee Lease Description [Line Items]
Operating lease right of use asset	$ 6,078	$ 6,633
Total operating lease liability	$ 5,162	$ 5,693
Operating lease weighted average remaining lease term - years	11 years	10 years
Operating lease weighted average discount rate - percent	2.90%	3.20%
Operating Lease [Member] \| Other Current Assets [Member]
Lessee Lease Description [Line Items]
Operating lease right of use asset	$ 6,078	$ 6,633
Operating Lease [Member] \| Accounts Payable And Accrued Liabilities [Member]
Lessee Lease Description [Line Items]
Operating lease liability - current included in Accounts payable and accrued liabilities	1,168	1,211
Operating Lease [Member] \| Other Long-Term Obligations [Member]
Lessee Lease Description [Line Items]
Operating lease liability - noncurrent included in Other long-term obligations	3,994	4,482
Drilling Rigs and Related Equipment [Member]
Lessee Lease Description [Line Items]
Operating lease right of use asset	834	572
Total operating lease liability	$ 832	$ 551
Operating lease weighted average remaining lease term - years	5 years	4 years
Operating lease weighted average discount rate - percent	2.20%	3.10%
Drilling Rigs and Related Equipment [Member] \| Other Current Assets [Member]
Lessee Lease Description [Line Items]
Operating lease right of use asset	$ 834	$ 572
Drilling Rigs and Related Equipment [Member] \| Accounts Payable And Accrued Liabilities [Member]
Lessee Lease Description [Line Items]
Operating lease liability - current included in Accounts payable and accrued liabilities	243	221
Drilling Rigs and Related Equipment [Member] \| Other Long-Term Obligations [Member]
Lessee Lease Description [Line Items]
Operating lease liability - noncurrent included in Other long-term obligations	589	330
Other [Member]
Lessee Lease Description [Line Items]
Operating lease right of use asset	5,244	6,061
Total operating lease liability	$ 4,330	$ 5,142
Operating lease weighted average remaining lease term - years	12 years	11 years
Operating lease weighted average discount rate - percent	3.00%	3.20%
Other [Member] \| Other Current Assets [Member]
Lessee Lease Description [Line Items]
Operating lease right of use asset	$ 5,244	$ 6,061
Other [Member] \| Accounts Payable And Accrued Liabilities [Member]
Lessee Lease Description [Line Items]
Operating lease liability - current included in Accounts payable and accrued liabilities	925	990
Other [Member] \| Other Long-Term Obligations [Member]
Lessee Lease Description [Line Items]
Operating lease liability - noncurrent included in Other long-term obligations	3,405	4,152
Finance Lease [Member]
Lessee Lease Description [Line Items]
Finance lease right of use asset	2,188	1,997
Total finance lease liability	$ 1,921	$ 1,908
Finance lease weighted average remaining lease term - years	20 years	20 years
Finance lease weighted average discount rate - percent	8.90%	9.70%
Finance Lease [Member] \| Property, Plant And Equipment [Member]
Lessee Lease Description [Line Items]
Finance lease right of use asset	$ 2,188	$ 1,997
Finance Lease [Member] \| Accounts Payable And Accrued Liabilities [Member]
Lessee Lease Description [Line Items]
Finance lease liability - current	4	15
Finance Lease [Member] \| Notes And Loans Payable [Member]
Lessee Lease Description [Line Items]
Finance lease liability - current	102	84
Finance Lease [Member] \| Long-Term Debt [Member]
Lessee Lease Description [Line Items]
Finance lease liability - noncurrent	1,680	1,670
Finance Lease [Member] \| Long-Term Obligations To Equity Companies [Member]
Lessee Lease Description [Line Items]
Finance lease liability - noncurrent	$ 135	$ 139

Leases (Maturity Schedule) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Operating Lease [Member]
Lessee Lease Description [Line Items]
Operating lease - 2021	$ 1,290
Operating lease - 2022	1,073
Operating lease - 2023	579
Operating lease - 2024	458
Operating lease - 2025	413
Operating lease - 2026 and beyond	2,281
Total operating lease payments	6,094
Operating lease - discount to present value	(932)
Total operating lease liability	5,162	$ 5,693
Drilling Rigs and Related Equipment [Member]
Lessee Lease Description [Line Items]
Operating lease - 2021	259
Operating lease - 2022	256
Operating lease - 2023	97
Operating lease - 2024	71
Operating lease - 2025	71
Operating lease - 2026 and beyond	124
Total operating lease payments	878
Operating lease - discount to present value	(46)
Total operating lease liability	832	551
Other [Member]
Lessee Lease Description [Line Items]
Operating lease - 2021	1,031
Operating lease - 2022	817
Operating lease - 2023	482
Operating lease - 2024	387
Operating lease - 2025	342
Operating lease - 2026 and beyond	2,157
Total operating lease payments	5,216
Operating lease - discount to present value	(886)
Total operating lease liability	4,330	5,142
Finance Lease [Member]
Lessee Lease Description [Line Items]
Finance lease - 2021	268
Finance lease - 2022	259
Finance lease - 2023	252
Finance lease - 2024	247
Finance lease - 2025	240
Finance lease - 2026 and beyond	2,544
Total finance lease payments	3,810
Finance lease - discount to present value	(1,889)
Total finance lease liability	$ 1,921	$ 1,908

Leases (Other Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Operating Lease [Member]
Lessee Lease Description [Line Items]
Cash flows from operating activities	$ 1,159	$ 1,116
Cash flow from investing activities	283	258
For January 1 adoption of ASC 842			$ 3,263
Operating right-of-use assets obtained in exchange for new lease liabilities	735	3,663
Drilling Rigs and Related Equipment [Member]
Lessee Lease Description [Line Items]
Cash flow from investing activities	283	258
For January 1 adoption of ASC 842			445
Operating right-of-use assets obtained in exchange for new lease liabilities	552	350
Other [Member]
Lessee Lease Description [Line Items]
Cash flows from operating activities	1,159	1,116
For January 1 adoption of ASC 842			$ 2,818
Operating right-of-use assets obtained in exchange for new lease liabilities	183	3,313
Finance Lease Paid To Equity Company [Member]
Lessee Lease Description [Line Items]
Cash flows from operating activities - finance leases	31	54
Finance Lease Paid To Third Parties [Member]
Lessee Lease Description [Line Items]
Cash flow from financing activities	94	177
Finance right-of-use assets obtained in exchange for new lease liabilities	$ 108	$ 422

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings per common share
Net income (loss) attributable to ExxonMobil	$ (22,440)	$ 14,340	$ 20,840
Weighted average number of common shares outstanding	4,271	4,270	4,270
Earnings (Loss) per common share (dollars)	$ (5.25)	$ 3.36	$ 4.88
Dividends paid per common share (dollars)	$ 3.48	$ 3.43	$ 3.23

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(19))
-URI http://asc.fasb.org/extlink&oid=116637232&loc=SL114874131-224263

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=117326831&loc=d3e1337-109256

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 55
-Paragraph 52
-URI http://asc.fasb.org/extlink&oid=117327953&loc=d3e4984-109258

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(21))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=117326831&loc=d3e1252-109256

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(23))
-URI http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=117326831&loc=SL5780133-109256

+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Financial Instruments And Derivatives (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Additions to long-term debt	$ 23,186	$ 7,052	$ 46
Initial margin collateral receivable	504	$ 379
Exxon Mobil Corporation [Member]
Additions to long-term debt	$ 23,000

Financial Instruments And Derivatives - Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Total Gross Assets & Liabilities [Domain]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative assets	$ 1,441	$ 635
Advances to/receivables from equity companies	9,179	8,670
Other long-term financial assets	2,179	2,119
Derivative liabilities	1,697	638
Long-term debt	50,392	25,789
Long-term obligations to equity companies	3,530	4,245
Other long-term financial liabilities	964	1,042
Effect Of Counterparty Netting [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative assets	(1,282)	(463)
Derivative liabilities	(1,282)	(463)
Effect Of Collateral Netting [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative assets	(6)	(70)
Derivative liabilities	(202)	(105)
Difference In Carrying Value And Fair Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Advances to/receivables from equity companies	(367)	(128)
Other long-term financial assets	125	44
Long-term debt	(4,890)	(1,117)
Long-term obligations to equity companies	(277)	(257)
Other long-term financial liabilities	44	16
Net Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative assets	153	102
Advances to/receivables from equity companies	8,812	8,542
Other long-term financial assets	2,304	2,163
Derivative liabilities	213	70
Long-term debt	45,502	24,672
Long-term obligations to equity companies	3,253	3,988
Other long-term financial liabilities	1,008	1,058
Level 1 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative assets	1,247	533
Other long-term financial assets	1,235	1,145
Derivative liabilities	1,443	568
Long-term debt	50,263	25,652
Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative assets	194	102
Advances to/receivables from equity companies	3,275	1,941
Derivative liabilities	254	70
Long-term debt	125	134
Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Advances to/receivables from equity companies	5,904	6,729
Other long-term financial assets	944	974
Long-term debt	4	3
Long-term obligations to equity companies	3,530	4,245
Other long-term financial liabilities	$ 964	$ 1,042

Financial Instruments and Derivatives - Derivative Instrument Balance Sheet (Details) bbl in Millions, MMBTU in Millions	12 Months Ended
	Dec. 31, 2020 MMBTU bbl	Dec. 31, 2019 MMBTU bbl
Crude Oil [Member] \| Long [Member]
Net notional long / short position of derivative instruments bbl	40	57
Petroleum Products [Member] \| Short [Member]
Net notional long / short position of derivative instruments bbl	46	38
Natural Gas [Member] \| Short [Member]
Net notional long / short position of derivative instruments MMBtus \| MMBTU	500	165

Financial Instruments and Derivatives - Derivative Instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Realized and Unrealized Before-Tax Gain / Loss on Derivative Instruments Recognized in the Consolidated Statement of Income
Sales and other operating revenue	$ 178,574	$ 255,583	$ 279,332
Crude oil and product purchases	94,007	143,801	156,172
Not Designated As Hedging Instrument, Trading [Member]
Realized and Unrealized Before-Tax Gain / Loss on Derivative Instruments Recognized in the Consolidated Statement of Income
Sales and other operating revenue	404	(412)	130
Crude oil and product purchases	(407)	179	(120)
Total	$ (3)	$ (233)	$ 10

Long-Term Debt (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Long-term Debt [Line Items]
Long-term debt in U.S. dollars	$ 41,026
U.S. dollar equivalent at year-end exchange rates of amounts payable in foreign currencies	6,156
Portion of long-term debt included in current liability	2,930
Additions to long-term debt	23,186	$ 7,052	$ 46
Long-term debt maturing - 2022	3,340
Long-term debt maturing - 2023	4,024
Long-term debt maturing - 2024	3,968
Long-term debt maturing - 2025	4,672
Net investment hedge, European business	5,500
Exxon Mobil Corporation [Member]
Long-term Debt [Line Items]
Additions to long-term debt	23,000
Long Term Financing [Member]
Long-term Debt [Line Items]
Unused credit lines	$ 0

Long-Term Debt (Summarized Long-Term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Long-term Debt [Line Items]
Debt issuance costs	$ (131)	$ (60)
Long-term debt	47,182	26,342
Exxon Mobil Corporation [Member]
Long-term Debt [Line Items]
Debt instrument, unamortized premium	148
XTO Energy Inc. [Member]
Long-term Debt [Line Items]
Debt instrument, unamortized premium	87	92
Combined Exxon Mobil And Affiliates [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Other long-term debt	78	89
Combined Exxon Mobil And Affiliates [Member] \| Other Foreign Currency Obligations [Member]
Long-term Debt [Line Items]
Other long-term debt	61	64
2.222% Notes Due 2021 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 0	2,500
Interest rate	2.222%
2.397% Notes Due 2022 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,150	1,150
Interest rate	2.397%
1.902% Notes Due 2022 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 750	750
Interest rate	1.902%
Floating-Rate Notes Due 2022 (Issued 2015) [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 500	500
Average effective interest rate	1.118%
Floating-Rate Notes Due 2022 (Issued 2019) [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 750	750
Average effective interest rate	1.189%
1.571% Notes Due 2023 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 2,750	0
Interest rate	1.571%
2.726% Notes Due 2023 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,250	1,250
Interest rate	2.726%
3.176% Notes Due 2024 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,000	1,000
Interest rate	3.176%
2.019% Notes Due 2024 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,000	1,000
Interest rate	2.019%
2.709% Notes Due 2025 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,750	1,750
Interest rate	2.709%
2.992% Notes Due 2025 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 2,807	0
Interest rate	2.992%
3.043% Notes Due 2026 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 2,500	2,500
Interest rate	3.043%
2.275% Notes Due 2026 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,000	1,000
Interest rate	2.275%
3.294% Notes Due 2027 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,000	0
Interest rate	3.294%
2.440% Notes Due 2029 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,250	1,250
Interest rate	2.44%
3.482% Notes Due 2030 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 2,000	0
Interest rate	3.482%
2.610% Notes Due 2030 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 2,000	0
Interest rate	2.61%
2.995% Notes Due 2039 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 750	750
Interest rate	2.995%
4.227% Notes Due 2040 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 2,091	0
Interest rate	4.227%
3.567% Notes Due 2045 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,000	1,000
Interest rate	3.567%
4.114% Notes Due 2046 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 2,500	2,500
Interest rate	4.114%
3.095% Notes Due 2049 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,500	1,500
Interest rate	3.095%
4.327% Notes Due 2050 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 2,750	0
Interest rate	4.327%
3.452% Notes Due 2051 [Member] \| Exxon Mobil Corporation [Member] \| Other U.S. Dollar Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 2,750	0
Interest rate	3.452%
0.142% Notes Due 2024 [Member] \| Exxon Mobil Corporation Euro-Denominated [Member] \| Other Foreign Currency Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,841	0
Interest rate	0.142%
0.524% Notes Due 2028 [Member] \| Exxon Mobil Corporation Euro-Denominated [Member] \| Other Foreign Currency Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,227	0
Interest rate	0.524%
0.835% Notes Due 2032 [Member] \| Exxon Mobil Corporation Euro-Denominated [Member] \| Other Foreign Currency Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,227	0
Interest rate	0.835%
1.408% Notes Due 2039 [Member] \| Exxon Mobil Corporation Euro-Denominated [Member] \| Other Foreign Currency Obligations [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 1,227	0
Interest rate	1.408%
6.100% Senior Notes Due 2036 [Member] \| XTO Energy Inc. [Member] \| Senior Notes [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 192	193
Interest rate	6.10%
6.750% Senior Notes Due 2037 [Member] \| XTO Energy Inc. [Member] \| Senior Notes [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 294	296
Interest rate	6.75%
6.375% Senior Notes Due 2038 [Member] \| XTO Energy Inc. [Member] \| Senior Notes [Member]
Long-term Debt [Line Items]
Senior notes, noncurrent	$ 227	229
Interest rate	6.375%
8.625% Debentures Due 2021 [Member] \| Mobil Corporation [Member] \| Debentures [Member]
Long-term Debt [Line Items]
Other long-term debt	$ 0	250
Interest rate	8.625%
Industrial Revenue Bonds Due 2022-2051 [Member] \| Combined Exxon Mobil And Affiliates [Member]
Long-term Debt [Line Items]
Other long-term debt	$ 2,461	2,461
Average effective interest rate	0.437%
Finance Lease Obligations [Member] \| Combined Exxon Mobil And Affiliates [Member]
Long-term Debt [Line Items]
Finance lease obligations	$ 1,680	$ 1,670
Average effective interest rate	8.73%

Incentive Program (Narrative) (Details) - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Minimum ownership of affiliates needed for awards	50.00%
Options and stock appreciation rights grant, minimum percentage of market value, date of grant	100.00%
Share-based compensation arrangement by share-based payment award expiration period	10 years
Number of shares issuable under 2003 incentive program, maximum	220,000
Remaining shares available for award under 2003 incentive program	71,000
Restricted Stock [Member]
Long-term incentive awards	8,681	8,936	8,771
Percent of the shares in each award vesting after three years	50.00%
Percent of shares in each award vesting after five years	50.00%
Percent of the shares in each award vesting after seven years	50.00%
Percent of shares in each award vesting in later of ten years or retirement	50.00%
Unrecognized compensation cost	$ 1,356
Unrecognized compensation cost, weighted-average period of recognition, years	4 years 2 months 12 days
Compensation cost charged against income	$ 672	$ 741	$ 774
Income tax benefit recognized in income	51	51	42
Fair value of shares/awards vested	367	647	722
Cash payments, vested restricted stock units	$ 34	$ 56	$ 61
Restricted Stock [Member] \| Minimum [Member]
Vesting Period	3 years
Restricted Stock [Member] \| Minimum [Member] \| Executive Officer [Member]
Vesting Period	5 years
Restricted Stock [Member] \| Maximum [Member]
Vesting Period	7 years
Restricted Stock [Member] \| Maximum [Member] \| Executive Officer [Member] \| Share-based Payment Arrangement, Tranche One [Member]
Vesting Period	10 years
Restricted Stock [Member] \| Maximum [Member] \| Executive Officer [Member] \| Share-based Payment Arrangement, Tranche Two [Member]
Vesting Period	10 years

Incentive Program (Summary Of Restricted Stock And Units Outstanding) (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2020 $ / shares shares
Share-based Payment Arrangement [Abstract]
Issued and outstanding at January 1, Restricted stock, Shares \| shares	39,628
Awards issued in 2020, Shares \| shares	9,030
Vested, Shares \| shares	(8,990)
Forfeited, Shares \| shares	(83)
Issued and outstanding at December 31, Restricted stock, Shares \| shares	39,585
Issued and outstanding at January 1, Weighted Average Grant-Date Fair Value per Share \| $ / shares	$ 84.50
Awards issued in 2020, Weighted Average Grant-Date Fair Value per Share \| $ / shares	68.95
Vested, Weighted Average Grant-Date Fair Value per Share \| $ / shares	86.84
Forfeited, Weighted Average Grant-Date Fair Value per Share \| $ / shares	82.04
Issued and outstanding at December 31, Weighted Average Grant-Date Fair Value per Share \| $ / shares	$ 80.43

Incentive Program (Grant Value Of Restricted Stock Units) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grant price, per share	$ 41.15	$ 68.77	$ 77.66
Units settled in stock	$ 325	$ 559	$ 620
Units settled in cash	32	55	61
Total value	$ 357	$ 614	$ 681

Litigation And Other Contingencies (Narrative) (Details) - USD ($) $ in Millions	Mar. 09, 2017	Oct. 09, 2014	Oct. 24, 2011	Jun. 27, 2007
Mobil Cerro Negro, Ltd. (MCN) [Member] \| Expropriation of Assets [Member]
Litigation And Other Contingencies [Line Items]
Percentage ownership interest in Cerro Negro Project				41.67%
Cerro Negro award for breach of contractual obligations		$ 908
Annulled Portion Of Award For Cerro Negro Project	$ 1,400
Retained and paid portion of award for Cerro Negro and La Ceiba Projects	$ 260
Nigeria Production Sharing Contract Litigation [Member]
Litigation And Other Contingencies [Line Items]
Percent interest in Erha block PSC			56.25%
Pending Or Threatened Litigation [Member]
Litigation And Other Contingencies [Line Items]
Amount of award relating to excess lifting of crude oil			$ 1,800
Accrued interest relating to award for excess lifting of crude oil			$ 234

Litigation And Other Contingencies (Schedule Of Guarantees) (Details) $ in Millions	Dec. 31, 2020 USD ($)
Loss Contingencies [Line Items]
Guarantees	$ 6,799
Equity Company Obligations [Member]
Loss Contingencies [Line Items]
Guarantees	1,731
Other Third-Party Obligations [Member]
Loss Contingencies [Line Items]
Guarantees	5,068
Debt-Related Guarantees [Member]
Loss Contingencies [Line Items]
Guarantees	1,110
Debt-Related Guarantees [Member] \| Equity Company Obligations [Member]
Loss Contingencies [Line Items]
Guarantees	986
Debt-Related Guarantees [Member] \| Other Third-Party Obligations [Member]
Loss Contingencies [Line Items]
Guarantees	124
Other Guarantees [Member]
Loss Contingencies [Line Items]
Guarantees	5,689
Other Guarantees [Member] \| Equity Company Obligations [Member]
Loss Contingencies [Line Items]
Guarantees	745
Other Guarantees [Member] \| Other Third-Party Obligations [Member]
Loss Contingencies [Line Items]
Guarantees	$ 4,944

Pension And Other Postretirement Benefits (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate	4.50%
Year that rate reaches ultimate trend rate	2022
Costs for defined contribution plans	$ 358	$ 422	$ 391
U.S. [Member] \| Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation	30.00%
U.S. [Member] \| Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation	70.00%
U.S. [Member] \| Venture Capital Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation	4.00%
Pension Benefits - Non-U.S. [Member] \| Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation	30.00%
Pension Benefits - Non-U.S. [Member] \| Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation	70.00%
Pension Benefits - Non-U.S. [Member] \| Venture Capital Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation	2.00%

Pension And Other Postretirement Benefits (Benefit Obligations And Plan Assets Associated With Principal Benefit Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Medicare subsidy receipts	$ 16	$ 20
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.80%	3.50%
Long-term rate of compensation increase	5.50%	5.75%
Benefit obligation at January 1	$ 20,959	$ 18,174
Service cost	965	757	$ 819
Interest cost	708	766	721
Defined benefit plan, actuarial net (gains) losses	1,287	2,562
Benefits paid	(1,987)	(1,300)
Amendments, divestments and other	(270)	0
Benefit obligation at December 31	21,662	20,959	18,174
Accumulated benefit obligation at December 31	$ 17,502	$ 16,387
Pension Benefits - Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	1.60%	2.30%
Long-term rate of compensation increase	4.20%	4.80%
Benefit obligation at January 1	$ 29,918	$ 25,378
Service cost	707	551	608
Interest cost	657	763	754
Defined benefit plan, actuarial net (gains) losses	2,344	3,703
Benefits paid	(1,317)	(1,196)
Foreign exchange rate changes	1,375	391
Amendments, divestments and other	(58)	328
Benefit obligation at December 31	33,626	29,918	25,378
Accumulated benefit obligation at December 31	$ 30,952	$ 27,236
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.80%	3.50%
Long-term rate of compensation increase	5.50%	5.75%
Benefit obligation at January 1	$ 8,113	$ 7,471
Service cost	181	139	152
Interest cost	277	315	301
Defined benefit plan, actuarial net (gains) losses	(66)	556
Benefits paid	(510)	(517)
Foreign exchange rate changes	23	25
Amendments, divestments and other	117	124
Benefit obligation at December 31	$ 8,135	$ 8,113	$ 7,471

Pension And Other Postretirement Benefits (Change In Plan Assets Of Pension And Other Postretirement Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value at January 1	$ 13,636	$ 11,134
Actual return on plan assets	2,269	2,521
Company contribution	1,004	1,022
Benefits paid	(1,609)	(1,041)
Fair value at December 31	15,300	13,636
Pension Benefits - Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value at January 1	22,916	19,486
Actual return on plan assets	2,795	3,210
Foreign exchange rate changes	1,011	513
Company contribution	597	602
Benefits paid	(992)	(883)
Other	(111)	(12)
Fair value at December 31	26,216	22,916
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value at January 1	425	386
Actual return on plan assets	42	54
Company contribution	37	41
Benefits paid	(58)	(56)
Fair value at December 31	$ 446	$ 425

Pension And Other Postretirement Benefits (Summary Of Assets In Excess Of/(Less Than) Benefit Obligation) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan funded status of plan	$ (4,156)	$ (4,656)
Unfunded plans	(2,206)	(2,667)
Total	(6,362)	(7,323)
Pension Benefits - Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan funded status of plan	(1,223)	(1,728)
Unfunded plans	(6,187)	(5,274)
Total	$ (7,410)	$ (7,002)

Pension And Other Postretirement Benefits (Assets Recorded In Balance Sheet And Other Comprehensive Income) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Postretirement benefits reserves	$ (22,415)	$ (22,304)
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance at December 31	(6,362)	(7,323)
Current liabilities	(377)	(242)
Postretirement benefits reserves	(5,985)	(7,081)
Total recorded	(6,362)	(7,323)
Net actuarial loss/(gain)	3,102	3,971
Prior service cost	(275)	1
Total recorded in accumulated other comprehensive income	2,827	3,972
Pension Benefits - Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance at December 31	(7,410)	(7,002)
Other assets	1,931	1,151
Current liabilities	(273)	(267)
Postretirement benefits reserves	(9,068)	(7,886)
Total recorded	(7,410)	(7,002)
Net actuarial loss/(gain)	5,904	5,662
Prior service cost	208	360
Total recorded in accumulated other comprehensive income	6,112	6,022
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance at December 31	(7,689)	(7,688)
Current liabilities	(327)	(351)
Postretirement benefits reserves	(7,362)	(7,337)
Total recorded	(7,689)	(7,688)
Net actuarial loss/(gain)	1,164	1,339
Prior service cost	(274)	(315)
Total recorded in accumulated other comprehensive income	$ 890	$ 1,024

Pension And Other Postretirement Benefits (Long-Term Rates Of Pension And Other Postretirement Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Total recorded in other comprehensive income	$ (1,189)	$ 2,041	$ (1,657)
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.50%	4.40%	3.80%
Long-term rate of return on funded assets	5.30%	5.30%	6.00%
Long-term rate of compensation increase	5.75%	5.75%	5.75%
Service cost	$ 965	$ 757	$ 819
Interest cost	708	766	721
Expected return on plan assets	(703)	(568)	(727)
Amortization of actuarial loss/(gain)	310	305	362
Amortization of prior service cost	5	5	5
Net pension enhancement and curtailment/settlement cost	280	164	268
Net periodic benefit cost	1,565	1,429	1,448
Net actuarial loss/(gain)	(279)	609	479
Amortization of actuarial (loss)/gain	(590)	(469)	(630)
Prior service cost/(credit)	(271)	0	0
Amortization of prior service (cost)/credit	(5)	(5)	(5)
Total recorded in other comprehensive income	(1,145)	135	(156)
Total recorded in net periodic benefit cost and other comprehensive income, before tax	$ 420	$ 1,564	$ 1,292
Pension Benefits - Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.30%	3.00%	2.80%
Long-term rate of return on funded assets	4.10%	4.10%	4.70%
Long-term rate of compensation increase	4.80%	4.30%	4.30%
Service cost	$ 707	$ 551	$ 608
Interest cost	657	763	754
Expected return on plan assets	(897)	(777)	(951)
Amortization of actuarial loss/(gain)	416	306	409
Amortization of prior service cost	68	56	46
Net pension enhancement and curtailment/settlement cost	49	(98)	44
Net periodic benefit cost	1,000	801	910
Net actuarial loss/(gain)	446	1,268	(66)
Amortization of actuarial (loss)/gain	(442)	(208)	(453)
Prior service cost/(credit)	(82)	379	98
Amortization of prior service (cost)/credit	(68)	(56)	(46)
Foreign exchange rate changes	236	19	(356)
Total recorded in other comprehensive income	90	1,402	(823)
Total recorded in net periodic benefit cost and other comprehensive income, before tax	$ 1,090	$ 2,203	$ 87
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.50%	4.40%	3.80%
Long-term rate of return on funded assets	4.60%	4.60%	6.00%
Long-term rate of compensation increase	5.75%	5.75%	5.75%
Service cost	$ 181	$ 139	$ 152
Interest cost	277	315	301
Expected return on plan assets	(18)	(15)	(23)
Amortization of actuarial loss/(gain)	95	55	116
Amortization of prior service cost	(42)	(42)	(40)
Net periodic benefit cost	493	452	506
Net actuarial loss/(gain)	(92)	517	(594)
Amortization of actuarial (loss)/gain	(95)	(55)	(116)
Prior service cost/(credit)	0	0	0
Amortization of prior service (cost)/credit	42	42	40
Foreign exchange rate changes	11	0	(8)
Total recorded in other comprehensive income	(134)	504	(678)
Total recorded in net periodic benefit cost and other comprehensive income, before tax	$ 359	$ 956	$ (172)

Pension And Other Postretirement Benefits (Summary Of The Change In Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Total (charge)/credit to other comprehensive income, before tax	$ 1,189	$ (2,041)	$ 1,657
(Charge)/credit to income tax (see Note 4)	(153)	550	(470)
(Charge)/credit to investment in equity companies	(110)	(19)	24
(Charge)/credit to other comprehensive income including noncontrolling interests, after tax	926	(1,510)	1,211
Charge/(credit) to equity of noncontrolling interests	30	146	(114)
Exxon Mobil Corporation Share After Noncontrolling Interest [Member]
Defined Benefit Plan Disclosure [Line Items]
Total change in accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment	956	(1,364)	1,097
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (charge)/credit to other comprehensive income, before tax	1,145	(135)	156
Pension Benefits - Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (charge)/credit to other comprehensive income, before tax	(90)	(1,402)	823
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (charge)/credit to other comprehensive income, before tax	$ 134	$ (504)	$ 678

Pension And Other Postretirement Benefits (Fair Value Of Benefit Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 15,300	$ 13,636	$ 11,134
U.S. [Member] \| Total At Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	4,886	4,226
Fair value of plan assets	15,293	13,628
U.S. [Member] \| U.S. Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	2,323	1,960
Fair value of plan assets	2,323	1,960
U.S. [Member] \| Non-U.S. Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	1,703	1,656
Fair value of plan assets	1,703	1,656
U.S. [Member] \| Private Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	548	499
Fair value of plan assets	548	499
U.S. [Member] \| Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	1	1
Fair value of plan assets	5,147	4,933
U.S. [Member] \| Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	2	2
Fair value of plan assets	5,263	4,472
U.S. [Member] \| Asset-Backed Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	1	1
Fair value of plan assets	1	1
U.S. [Member] \| Cash [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	308	107
Fair value of plan assets	308	107
U.S. [Member] \| Insurance Contracts At Contract Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7	8
U.S. [Member] \| Fair Value Inputs Level 2 [Member] \| Total At Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	10,407	9,402
U.S. [Member] \| Fair Value Inputs Level 2 [Member] \| Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	5,146	4,932
U.S. [Member] \| Fair Value Inputs Level 2 [Member] \| Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	5,261	4,470
Pension Benefits - Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	26,216	22,916	$ 19,486
Pension Benefits - Non-U.S. [Member] \| Total At Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	25,486	22,210
Fair value of plan assets	26,193	22,894
Pension Benefits - Non-U.S. [Member] \| U.S. Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	4,177	3,436
Fair value of plan assets	4,177	3,436
Pension Benefits - Non-U.S. [Member] \| Non-U.S. Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	3,285	3,015
Fair value of plan assets	3,374	3,085
Pension Benefits - Non-U.S. [Member] \| Private Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	530	489
Fair value of plan assets	530	489
Pension Benefits - Non-U.S. [Member] \| Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	5,212	4,486
Fair value of plan assets	5,350	4,615
Pension Benefits - Non-U.S. [Member] \| Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	11,993	10,511
Fair value of plan assets	12,359	10,930
Pension Benefits - Non-U.S. [Member] \| Asset-Backed Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	239	212
Fair value of plan assets	263	233
Pension Benefits - Non-U.S. [Member] \| Cash [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	50	61
Fair value of plan assets	140	106
Pension Benefits - Non-U.S. [Member] \| Insurance Contracts At Contract Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	23	22
Pension Benefits - Non-U.S. [Member] \| Fair Value Inputs Level 1 [Member] \| Total At Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	408	383
Pension Benefits - Non-U.S. [Member] \| Fair Value Inputs Level 1 [Member] \| Non-U.S. Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	89	70
Pension Benefits - Non-U.S. [Member] \| Fair Value Inputs Level 1 [Member] \| Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	250	280
Pension Benefits - Non-U.S. [Member] \| Fair Value Inputs Level 1 [Member] \| Cash [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	69	33
Pension Benefits - Non-U.S. [Member] \| Fair Value Inputs Level 2 [Member] \| Total At Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	299	301
Pension Benefits - Non-U.S. [Member] \| Fair Value Inputs Level 2 [Member] \| Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	138	129
Pension Benefits - Non-U.S. [Member] \| Fair Value Inputs Level 2 [Member] \| Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	116	139
Pension Benefits - Non-U.S. [Member] \| Fair Value Inputs Level 2 [Member] \| Asset-Backed Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	24	21
Pension Benefits - Non-U.S. [Member] \| Fair Value Inputs Level 2 [Member] \| Cash [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	$ 21	$ 12

Pension And Other Postretirement Benefits (Fair Value Of Benefit Plan Assets - Other Postretirement) (Details) - Other Postretirement Benefit Plans Defined Benefit [Member] - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	$ 3	$ 133
Fair value of plan assets	446	425
U.S. Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	0	81
Fair value of plan assets	88	81
Non-U.S. Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	0	49
Fair value of plan assets	48	49
Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	103	92
Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	204	200
Cash [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, net asset value	3	3
Fair value of plan assets	3	3
Fair Value Inputs Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	136
Fair Value Inputs Level 1 [Member] \| U.S. Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	88
Fair Value Inputs Level 1 [Member] \| Non-U.S. Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	48
Fair Value Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	307	292
Fair Value Inputs Level 2 [Member] \| Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	103	92
Fair Value Inputs Level 2 [Member] \| Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, fair value hierarchy	$ 204	$ 200

Pension And Other Postretirement Benefits (Pension Plans With Accumulated Benefit Obligation In Excess Of Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Funded Pension Plans [Member] \| U.S. [Member]
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Accumulated benefit obligation	$ 16,129	$ 14,940
Fair value of plan assets	15,300	13,636
Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract]
Projected benefit obligation	19,456	18,292
Fair value of plan assets	15,300	13,636
Funded Pension Plans [Member] \| Pension Benefits - Non-U.S. [Member]
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Accumulated benefit obligation	4,602	3,026
Fair value of plan assets	2,652	1,381
Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract]
Projected benefit obligation	13,836	12,496
Fair value of plan assets	10,681	9,616
Unfunded Pension Plans [Member] \| U.S. [Member]
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Accumulated benefit obligation	1,373	1,447
Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract]
Projected benefit obligation	2,206	2,667
Unfunded Pension Plans [Member] \| Pension Benefits - Non-U.S. [Member]
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Accumulated benefit obligation	5,469	4,629
Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract]
Projected benefit obligation	$ 6,187	$ 5,274

Pension And Other Postretirement Benefits (Expected Contribution Pension Benefits And Other Postretirement Benefits) (Details) $ in Millions	Dec. 31, 2020 USD ($)
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions expected in 2021	$ 865
Benefits payments expected in 2021	2,434
Benefits payments expected in 2022	1,079
Benefits payments expected in 2023	1,105
Benefits payments expected in 2024	1,124
Benefits payments expected in 2025	1,142
Benefits payments expected in 2026-2030	5,971
Pension Benefits - Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions expected in 2021	395
Benefits payments expected in 2021	1,310
Benefits payments expected in 2022	1,193
Benefits payments expected in 2023	1,214
Benefits payments expected in 2024	1,240
Benefits payments expected in 2025	1,186
Benefits payments expected in 2026-2030	6,274
Gross Other Post Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefits payments expected in 2021	424
Benefits payments expected in 2022	426
Benefits payments expected in 2023	420
Benefits payments expected in 2024	418
Benefits payments expected in 2025	415
Benefits payments expected in 2026-2030	2,058
Other Postretirement Benefits Medicare Subsidy Receipt [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefits payments expected in 2021	22
Benefits payments expected in 2022	23
Benefits payments expected in 2023	25
Benefits payments expected in 2024	26
Benefits payments expected in 2025	27
Benefit payments expected in 2026-2030	$ 143

Disclosures About Segments And Related Information (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting, Measurement Disclosures [Abstract]
Non-debt-related interest expense	$ 148	$ 105	$ 84

Disclosures About Segments And Related Information (Schedule Of Segments And Related Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	$ (22,440)	$ 14,340	$ 20,840
Effect of asset impairments - noncash, after-tax	20,253
Earnings of equity companies included above	1,732	5,441	7,355
Sales and other operating revenue	178,574	255,583	279,332
Depreciation and depletion expense	46,009	18,998	18,745
Interest revenue	49	84	64
Interest expense	1,158	830	766
Income tax expense (benefit)	(5,632)	5,282	9,532
Additions to property, plant and equipment	17,342	24,904	20,051
Investments in equity companies	29,772	29,291	26,382
Total assets	332,750	362,597	346,196
U.S. [Member]
Segment Reporting Information [Line Items]
Sales and other operating revenue	62,663	89,612	96,930
Income tax expense (benefit)	(6,533)	(469)	1,145
Non-U.S. [Member]
Segment Reporting Information [Line Items]
Sales and other operating revenue	115,911	165,971	182,402
Income tax expense (benefit)	901	5,751	8,387
Upstream [Member] \| U.S. [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(19,385)	536	1,739
Effect of asset impairments - noncash, after-tax	17,138
Earnings of equity companies included above	(559)	282	608
Sales and other operating revenue	5,876	9,364	10,359
Intersegment revenue	8,508	10,893	8,683
Depreciation and depletion expense	28,627	6,162	6,024
Interest expense	52	54	77
Income tax expense (benefit)	(5,958)	(151)	104
Additions to property, plant and equipment	5,726	10,404	7,119
Investments in equity companies	4,792	5,313	4,566
Total assets	71,287	95,750	90,310
Upstream [Member] \| Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(645)	13,906	12,340
Effect of asset impairments - noncash, after-tax	2,287
Earnings of equity companies included above	2,101	4,534	5,816
Sales and other operating revenue	8,673	13,779	15,158
Intersegment revenue	19,642	30,864	29,659
Depreciation and depletion expense	12,723	9,305	9,257
Interest expense	93	34	31
Income tax expense (benefit)	742	5,509	8,149
Additions to property, plant and equipment	4,418	7,347	7,974
Investments in equity companies	18,135	17,736	16,337
Total assets	144,730	151,181	148,914
Downstream [Member] \| U.S. [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(852)	1,717	2,962
Effect of asset impairments - noncash, after-tax	15
Earnings of equity companies included above	134	196	156
Sales and other operating revenue	48,256	70,523	74,327
Intersegment revenue	12,258	22,416	21,954
Depreciation and depletion expense	716	674	684
Interest expense	1	1	2
Income tax expense (benefit)	(324)	465	946
Additions to property, plant and equipment	2,983	2,685	1,152
Investments in equity companies	352	319	293
Total assets	23,754	23,442	17,898
Downstream [Member] \| Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(225)	606	3,048
Effect of asset impairments - noncash, after-tax	609
Earnings of equity companies included above	(190)	19	(6)
Sales and other operating revenue	92,640	134,460	147,007
Intersegment revenue	15,162	24,775	29,888
Depreciation and depletion expense	1,672	832	890
Interest expense	21	9	12
Income tax expense (benefit)	393	361	1,008
Additions to property, plant and equipment	1,731	1,777	1,595
Investments in equity companies	879	1,062	1,162
Total assets	34,848	37,133	34,024
Chemical [Member] \| U.S. [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	1,277	206	1,642
Effect of asset impairments - noncash, after-tax	100
Earnings of equity companies included above	(21)	(4)	48
Sales and other operating revenue	8,529	9,723	12,239
Intersegment revenue	6,099	7,864	9,044
Depreciation and depletion expense	685	555	405
Income tax expense (benefit)	440	58	566
Additions to property, plant and equipment	1,221	1,344	1,146
Investments in equity companies	2,543	1,835	870
Total assets	17,839	16,544	14,904
Chemical [Member] \| Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	686	386	1,709
Effect of asset impairments - noncash, after-tax	69
Earnings of equity companies included above	651	818	1,113
Sales and other operating revenue	14,562	17,693	20,204
Intersegment revenue	3,881	5,905	7,217
Depreciation and depletion expense	694	621	606
Interest expense	0	1	1
Income tax expense (benefit)	272	305	245
Additions to property, plant and equipment	592	589	348
Investments in equity companies	3,514	3,335	3,431
Total assets	20,220	20,376	21,131
Corporate And Financing [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(3,296)	(3,017)	(2,600)
Effect of asset impairments - noncash, after-tax	35
Earnings of equity companies included above	(384)	(404)	(380)
Sales and other operating revenue	38	41	38
Intersegment revenue	221	224	205
Depreciation and depletion expense	892	849	879
Interest revenue	49	84	64
Interest expense	991	731	643
Income tax expense (benefit)	(1,197)	(1,265)	(1,486)
Additions to property, plant and equipment	671	758	717
Investments in equity companies	(443)	(309)	(277)
Total assets	$ 20,072	$ 18,171	$ 19,015

Disclosures About Segments And Related Information (Schedule Of Geographic Sales And Other Operating Revenue) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Revenue Reconciling Item [Line Items]
Sales and other operating revenue	$ 178,574	$ 255,583	$ 279,332
U.S. [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Sales and other operating revenue	62,663	89,612	96,930
Non-U.S. [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Sales and other operating revenue	115,911	165,971	182,402
Canada [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Sales and other operating revenue	13,093	19,735	22,672
United Kingdom [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Sales and other operating revenue	11,055	17,479	18,702
Singapore [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Sales and other operating revenue	9,442	12,128	13,689
France [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Sales and other operating revenue	8,676	12,740	13,637
Italy [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Sales and other operating revenue	7,091	10,459	13,396
Belgium [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Sales and other operating revenue	6,231	11,644	15,664
Australia [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Sales and other operating revenue	$ 5,839	$ 7,941	$ 8,780

Disclosures About Segments And Related Information (Schedule Of Long-Lived Assets By Geographic Regions) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 227,553	$ 253,018	$ 247,101
U.S. [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	94,732	114,372	108,147
Non-U.S. [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	132,821	138,646	138,954
Canada [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	36,232	39,130	37,433
Australia [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	14,792	13,933	14,548
Singapore [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	12,129	11,645	11,148
Kazakhstan [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	8,882	9,315	9,726
Papua New Guinea [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	7,803	8,057	8,269
Nigeria [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	6,345	7,640	8,421
United Arab Emirates [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	5,381	5,262	4,859
Russia [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	4,616	5,135	5,456
Angola [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 4,405	$ 5,784	$ 7,021

Income And Other Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income And Other Taxes [Abstract]
Reconciliation between income tax expense and theoretical U.S. tax rate, statutory rate	21.00%	21.00%	21.00%
Potential percentage decrease in unrecognized tax benefits	10.00%
Potential percentage increase in unrecognized tax benefits	10.00%
Interest expense on income tax reserves	$ (6)	$ 0	$ 3
Interest payable on income tax reserves	61	71
Valuation Allowance [Abstract]
Asset valuation allowances	2,731	1,924
Valuation allowance change from 2019 to 2020	807
US Tax Reform [Member]
Income And Other Taxes [Abstract]
Net deferred income tax expense (credits)/charges for tax rate and law changes	0	0	(291)
Total US and Non US
Income And Other Taxes [Abstract]
Net deferred income tax expense (credits)/charges for tax rate and law changes	(25)	$ (740)	$ (289)
AssetImpairments [Member]
Income And Other Taxes [Abstract]
Net deferred income tax expense (credits)/charges for tax rate and law changes	(6,300)
Change in net provisions [Member]
Valuation Allowance [Abstract]
Valuation allowance change from 2019 to 2020	762
Effects of foreign currency translation [Member]
Valuation Allowance [Abstract]
Valuation allowance change from 2019 to 2020	$ 41

Income And Other Taxes (Schedule Of Income And Other Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income and Other Taxes [Line Items]
Current	$ 3,170	$ 6,050	$ 9,460
Deferred - net	(8,052)	(675)	(96)
U.S. tax on non-U.S. operations	13	89	42
Total federal and non-U.S.	(4,869)	5,464	9,406
State	(763)	(182)	126
Total income tax expense (benefit)	(5,632)	5,282	9,532
Other taxes and duties	26,122	30,525	32,663
Other taxes and duties included in production and manufacturing expenses	1,811	2,196	2,102
Other taxes and duties included in SG&A expenses	492	465	465
Total other taxes and duties	28,425	33,186	35,230
Total	22,793	38,468	44,762
U.S. [Member]
Income and Other Taxes [Line Items]
Current	262	(121)	459
Deferred - net	(6,045)	(255)	518
U.S. tax on non-U.S. operations	13	89	42
Total federal and non-U.S.	(5,770)	(287)	1,019
State	(763)	(182)	126
Total income tax expense (benefit)	(6,533)	(469)	1,145
Other taxes and duties	3,108	3,566	3,498
Other taxes and duties included in production and manufacturing expenses	1,148	1,385	1,245
Other taxes and duties included in SG&A expenses	164	160	153
Total other taxes and duties	4,420	5,111	4,896
Total	(2,113)	4,642	6,041
Non-U.S. [Member]
Income and Other Taxes [Line Items]
Current	2,908	6,171	9,001
Deferred - net	(2,007)	(420)	(614)
Total federal and non-U.S.	901	5,751	8,387
Total income tax expense (benefit)	901	5,751	8,387
Other taxes and duties	23,014	26,959	29,165
Other taxes and duties included in production and manufacturing expenses	663	811	857
Other taxes and duties included in SG&A expenses	328	305	312
Total other taxes and duties	24,005	28,075	30,334
Total	$ 24,906	$ 33,826	$ 38,721

Income And Other Taxes (Reconciliation Between Income Tax Expense And Theoretical U.S. Tax) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income And Other Taxes [Abstract]
United States income before income taxes	$ (27,704)	$ (53)	$ 5,200
Non-U.S. income before income taxes	(1,179)	20,109	25,753
Income (Loss) before income taxes	(28,883)	20,056	30,953
Theoretical tax	(6,065)	4,212	6,500
Effect of equity method of accounting	(364)	(1,143)	(1,545)
Non-U.S. taxes in excess of/(less than) theoretical U.S. tax	1,606	2,573	4,626
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount	(603)	(144)	100
Other	(206)	(216)	142
Total income tax expense (benefit)	(5,632)	5,282	9,532
ExxonMobil share of equity company income taxes	861	2,490	3,142
Total income tax expense (credit)	(4,771)	7,772	12,674
Net income (loss) including noncontrolling interests	(23,251)	14,774	21,421
Total income (loss) before taxes	$ (28,022)	$ 22,546	$ 34,095
Effective income tax rate	17.00%	34.00%	37.00%
Reconciliation between income tax expense and theoretical U.S. tax rate, statutory rate	21.00%	21.00%	21.00%
Effect of U.S. tax reform - noncash
Effective Tax Rate [Line Items]
Effect of U.S. tax reform	$ 0	$ 0	$ (291)
U.S. [Member]
Income And Other Taxes [Abstract]
Total income tax expense (benefit)	(6,533)	(469)	1,145
Effective Tax Rate [Line Items]
Deferred tax asset valuation allowances	115
Non-U.S. [Member]
Income And Other Taxes [Abstract]
Total income tax expense (benefit)	901	5,751	$ 8,387
Effective Tax Rate [Line Items]
Deferred tax asset valuation allowances	$ 647
Non-U.S. [Member] \| Benefit [Member]
Effective Tax Rate [Line Items]
Norway operations and the sale of upstream assets		(773)
Tax rate change in Alberta, Canada		(657)
Adjustment to prior year tax position charge/(benefit)		$ (268)

Income And Other Taxes (Deferred Income Taxes Assets And Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Income And Other Taxes [Abstract]
Property, plant and equipment	$ 28,778	$ 36,029
Other liabilities	6,427	7,653
Total deferred tax liabilities	35,205	43,682
Pension and other postretirement benefits	(4,703)	(4,712)
Asset retirement obligations	(3,150)	(3,403)
Tax loss carryforwards	(8,982)	(7,404)
Other assets	(7,095)	(7,735)
Total deferred tax assets	(23,930)	(23,254)
Asset valuation allowances	2,731	1,924
Net deferred tax liabilities	$ 14,006	$ 22,352

Income And Other Taxes (Deferred Income Tax (Assets) And Liabilities By Balance Sheet Classification) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Income And Other Taxes [Abstract]
Other assets, including intangibles, net	$ (4,159)	$ (3,268)
Deferred income tax liabilities	18,165	25,620
Net deferred tax liabilities	$ 14,006	$ 22,352

Income And Other Taxes (Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income And Other Taxes [Abstract]
Balance at January 1	$ 8,844	$ 9,174	$ 8,783
Additions based on current year's tax positions	253	287	375
Additions for prior years' tax positions	218	120	240
Reductions for prior years' tax positions	(201)	(97)	(125)
Reductions due to lapse of the statute of limitations	(237)	(279)	(5)
Settlements with tax authorities	(113)	(538)	(68)
Foreign exchange effects/other	0	177	(26)
Balance at December 31	$ 8,764	$ 8,844	$ 9,174

Restructuring Activities (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring charges, workforce reduction programs, before-tax	$ 450
Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges, planned workforce reduction programs	200
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges, workforce reduction programs, before-tax	$ 450

Restructuring Activities (Summary of Reserves and Charges) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Restructuring Reserve [Roll Forward]
Balance at January 1, 2020, Workforce reduction program reserves and charges	$ 0
Additions/adjustments, Workforce reduction program reserves and charges	450
Payments made, Workforce reduction program reserves and charges	(47)
Balance at December 31, 2020, Workforce reduction program reserves and charges	$ 403

Income And Other Taxes (Remaining Tax Years Subject To Examination By Major Tax Jurisdiction) (Details)	12 Months Ended
	Dec. 31, 2020
Abu Dhabi [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2018
Abu Dhabi [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
Angola [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2018
Angola [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
Australia [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2010
Australia [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
Belgium [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2017
Belgium [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
Canada [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2001
Canada [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
Equatorial Guinea [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2007
Equatorial Guinea [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
Indonesia [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2007
Indonesia [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
Iraq [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2015
Iraq [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
Malaysia [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2011
Malaysia [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
Nigeria [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2006
Nigeria [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
Norway [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2010
Norway [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
Papua New Guinea [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2008
Papua New Guinea [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
Russia [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2018
Russia [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
United Kingdom [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2015
United Kingdom [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020
United States [Member] \| Earliest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2006
United States [Member] \| Latest Tax Year [Member]
Income and Other Taxes [Line Items]
Open tax years by major tax jurisdiction	2020