Marathon Oil (MRO) 10-Q 5 Aug 21 2021 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Jun. 30, 2021	Jul. 31, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	1-1513
Entity Registrant Name (tagged on cover)	Marathon Oil Corporation
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	25-0996816
Entity Address, Address Line One	5555 San Felipe Street,
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77056-2723
City Area Code	(713)
Local Phone Number	629-6600
Title of 12(b) Security	Common Stock, par value $1.00
Trading Symbol	MRO
Security Exchange Name	NYSE
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
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		788,398,843
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2021
Amendment Flag	false
Entity Central Index Key	0000101778
Current Fiscal Year End Date	--12-31

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues and other income:
Revenues from contracts with customers	$ 1,254	$ 490	$ 2,431	$ 1,514
Net gain (loss) on commodity derivatives	(166)	(70)	(319)	132
Income (loss) from equity method investments	49	(152)	93	(164)
Net gain (loss) on disposal of assets	1	(2)	1	7
Other income	5	6	8	13
Total revenues and other income	1,143	272	2,214	1,502
Costs and expenses:
Production	126	129	247	289
Shipping, handling and other operating	167	105	319	249
Exploration	25	26	46	54
Depreciation, depletion and amortization	532	597	1,028	1,241
Impairments	46	0	47	97
Taxes other than income	74	30	148	96
General and administrative	68	88	157	164
Total costs and expenses	1,038	975	1,992	2,190
Income (loss) from operations	105	(703)	222	(688)
Net interest and other	(59)	(69)	(72)	(133)
Other net periodic benefit (costs) credits	(1)	7	2	7
Loss on early extinguishment of debt	(19)	0	(19)	0
Income (loss) before income taxes	26	(765)	133	(814)
Provision (benefit) for income taxes	10	(15)	20	(18)
Net income (loss)	$ 16	$ (750)	$ 113	$ (796)
Net income (loss) per share:
Basic (in dollars per share)	$ 0.02	$ (0.95)	$ 0.14	$ (1)
Diluted (in dollars per share)	$ 0.02	$ (0.95)	$ 0.14	$ (1)
Weighted average common shares outstanding:
Basic (in shares)	789	790	790	793
Diluted (in shares)	789	790	791	793

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 16	$ (750)	$ 113	$ (796)
Other comprehensive income (loss), net of tax
Change in actuarial gain (loss) and other for postretirement and postemployment plans	16	(42)	13	(42)
Change in derivative hedges unrecognized gain (loss)	(21)	(4)	19	(26)
Reclassification of de-designated forward interest rate swaps	(30)	0	(28)	0
Other comprehensive income (loss)	(35)	(46)	4	(68)
Comprehensive income (loss)	$ (19)	$ (796)	$ 117	$ (864)

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 970	$ 742
Receivables, less reserve of $19 and $22	1,008	747
Inventories	78	76
Other current assets	19	47
Total current assets	2,075	1,612
Equity method investments	458	447
Property, plant and equipment, less accumulated depreciation, depletion and amortization of $21,364 and $20,358	15,019	15,638
Other noncurrent assets	248	259
Total assets	17,800	17,956
Current liabilities:
Accounts payable	937	837
Payroll and benefits payable	49	57
Accrued taxes	95	72
Other current liabilities	461	247
Long-term debt due within one year	33	0
Total current liabilities	1,575	1,213
Long-term debt	4,875	5,404
Deferred tax liabilities	156	163
Defined benefit postretirement plan obligations	151	180
Asset retirement obligations	272	241
Deferred credits and other liabilities	137	194
Total liabilities	7,166	7,395
Commitments and contingencies
Stockholders’ Equity
Preferred stock – no shares issued or outstanding (no par value, 26 million shares authorized)	0	0
Common stock:
Issued – 937 million shares (par value $1 per share, 1.925 billion shares authorized at June 30, 2021 and December 31, 2020)	937	937
Held in treasury, at cost – 148 million shares	(4,105)	(4,089)
Additional paid-in capital	7,201	7,174
Retained earnings	6,524	6,466
Accumulated other comprehensive income	77	73
Total stockholders’ equity	10,634	10,561
Total liabilities and stockholders’ equity	$ 17,800	$ 17,956

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Receivables reserve	$ 19	$ 22
Property, plant and equipment, accumulated depreciation	$ 21,364	$ 20,358
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	26,000,000	26,000,000
Common stock, shares issued (in shares)	937,000,000	937,000,000
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	1,925,000,000	1,925,000,000
Held in treasury, shares (in shares)	148,000,000	148,000,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating activities:
Net income (loss)	$ 113	$ (796)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	1,028	1,241
Impairments	47	97
Exploratory dry well costs and unproved property impairments	39	40
Net gain on disposal of assets	(1)	(7)
Loss on early extinguishment of debt	19	0
Deferred income taxes	(7)	(14)
Unrealized (gain) loss on derivative instruments, net	157	(75)
Pension and other post retirement benefits, net	(14)	(31)
Stock-based compensation	17	28
Equity method investments, net	(17)	180
Changes in:
Current receivables	(253)	489
Inventories	(2)	(5)
Current accounts payable and accrued liabilities	121	(456)
Other current assets and liabilities	73	46
All other operating, net	(43)	(27)
Net cash provided by operating activities	1,277	710
Investing activities:
Additions to property, plant and equipment	(483)	(946)
Additions to other assets	0	12
Acquisitions, net of cash acquired	0	3
Disposal of assets, net of cash transferred to the buyer	15	9
Equity method investments - return of capital	6	7
All other investing, net	(1)	0
Net cash used in investing activities	(463)	(915)
Financing activities:
Debt repayment	(500)	0
Debt extinguishment costs	(19)	0
Purchases of common stock	(9)	(92)
Dividends paid	(55)	(40)
All other financing, net	(3)	1
Net cash used in financing activities	(586)	(131)
Net increase (decrease) in cash and cash equivalents	228	(336)
Cash and cash equivalents at beginning of period	742	858
Cash and cash equivalents at end of period	$ 970	$ 522

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Preferred Stock	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Retained EarningsCumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2019	$ 12,153	$ (12)	$ 0	$ 937	$ (4,089)	$ 7,207	$ 7,993	$ (12)	$ 105
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - stock-based compensation	38				121	(83)
Shares repurchased	(91)				(91)
Stock-based compensation	(22)					(22)
Net income (loss)	(46)						(46)
Other comprehensive income (loss)	(22)								(22)
Dividends paid	(40)						(40)
Ending balance at Mar. 31, 2020	11,958		0	937	(4,059)	7,102	7,895		83
Beginning balance at Dec. 31, 2019	12,153	$ (12)	0	937	(4,089)	7,207	7,993	$ (12)	105
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(796)
Other comprehensive income (loss)	(68)
Ending balance at Jun. 30, 2020	11,175		0	937	(4,087)	7,143	7,145		37
Beginning balance at Mar. 31, 2020	11,958		0	937	(4,059)	7,102	7,895		83
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - stock-based compensation	(8)				(28)	20
Stock-based compensation	21					21
Net income (loss)	(750)						(750)
Other comprehensive income (loss)	(46)								(46)
Ending balance at Jun. 30, 2020	11,175		0	937	(4,087)	7,143	7,145		37
Beginning balance at Dec. 31, 2020	10,561		0	937	(4,089)	7,174	6,466		73
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - stock-based compensation	(5)				(15)	10
Shares repurchased	(9)				(9)
Stock-based compensation	11					11
Net income (loss)	97						97
Other comprehensive income (loss)	39								39
Dividends paid	(23)						(23)
Ending balance at Mar. 31, 2021	10,671		0	937	(4,113)	7,195	6,540		112
Beginning balance at Dec. 31, 2020	10,561		0	937	(4,089)	7,174	6,466		73
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	113
Other comprehensive income (loss)	4
Ending balance at Jun. 30, 2021	10,634		0	937	(4,105)	7,201	6,524		77
Beginning balance at Mar. 31, 2021	10,671		0	937	(4,113)	7,195	6,540		112
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - stock-based compensation	9				8	1
Shares repurchased	0				0
Stock-based compensation	5					5
Net income (loss)	16						16
Other comprehensive income (loss)	(35)								(35)
Dividends paid	(32)						(32)
Ending balance at Jun. 30, 2021	$ 10,634		$ 0	$ 937	$ (4,105)	$ 7,201	$ 6,524		$ 77

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Stockholders' Equity [Abstract]
Dividends paid (in dollars per share)	$ 0.04	$ 0.03	$ 0	$ 0.05	$ 0.07	$ 0.05

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation These consolidated financial statements are unaudited; however, in the opinion of management, these statements reflect all adjustments necessary for a fair statement of the results for the periods reported. All such adjustments are of a normal recurring nature unless disclosed otherwise. These consolidated financial statements, including notes, have been prepared in accordance with the applicable rules of the SEC and do not include all of the information and disclosures required by U.S. GAAP for complete financial statements. These interim financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in our 2020 Annual Report on Form 10-K. The results of operations for the second quarter and first six months of 2021 are not necessarily indicative of the results to be expected for the full year.

Accounting Standards

Accounting Standards	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Accounting Standards	Accounting StandardsNo accounting standards were adopted in the second quarter or first six months of 2021 that had a material impact on our consolidated financial statements.

Income (loss) and Dividends per

Income (loss) and Dividends per Common Share	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Income (loss) and Dividends per Common Share	Income (loss) and Dividends per Common Share Basic income (loss) per share is based on the weighted average number of common shares outstanding. Diluted income (loss) per share assumes exercise of stock options in all periods, provided the effect is not antidilutive. The per share calculations below exclude 4 million and 5 million of stock options for each of the three and six months ended June 30, 2021, respectively, and 7 million of stock options for each of the three and six months ended June 30, 2020 that were antidilutive. Three Months Ended June 30, Six Months Ended June 30, (In millions, except per share data) 2021 2020 2021 2020 Net income (loss) $ 16 $ (750) $ 113 $ (796) Weighted average common shares outstanding 789 790 790 793 Effect of dilutive securities — — 1 — Weighted average common shares, diluted 789 790 791 793 Net income (loss) per share: Basic $ 0.02 $ (0.95) $ 0.14 $ (1.00) Diluted $ 0.02 $ (0.95) $ 0.14 $ (1.00) Dividends per share $ 0.04 $ — $ 0.07 $ 0.05

Revenues

Revenues	6 Months Ended
	Jun. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenues	Revenues The majority of our revenues are derived from the sale of crude oil and condensate, NGLs and natural gas under spot and term agreements with our customers in the United States and Equatorial Guinea. As of June 30, 2021 and December 31, 2020, receivables from contracts with customers, included in receivables, less reserves were $841 million and $572 million, respectively. The following tables present our revenues from contracts with customers disaggregated by product type and geographic areas for the three and six months ended June 30 as follows: United States Three Months Ended June 30, 2021 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 353 $ 411 $ 71 $ 77 $ 24 $ 936 Natural gas liquids 33 48 37 11 2 131 Natural gas 29 17 41 5 (1) 91 Other 2 — — — 29 31 Revenues from contracts with customers $ 417 $ 476 $ 149 $ 93 $ 54 $ 1,189 Three Months Ended June 30, 2020 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 142 $ 147 $ 32 $ 33 $ 7 $ 361 Natural gas liquids 16 3 13 4 1 37 Natural gas 20 5 24 4 1 54 Other 1 — — — 9 10 Revenues from contracts with customers $ 179 $ 155 $ 69 $ 41 $ 18 $ 462 Six Months Ended June 30, 2021 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 612 $ 783 $ 132 $ 154 $ 46 $ 1,727 Natural gas liquids 59 89 74 20 5 247 Natural gas 76 42 150 30 8 306 Other 4 — — — 37 41 Revenues from contracts with customers $ 751 $ 914 $ 356 $ 204 $ 96 $ 2,321 Six Months Ended June 30, 2020 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 449 $ 477 $ 116 $ 107 $ 40 $ 1,189 Natural gas liquids 31 13 34 7 3 88 Natural gas 44 13 53 7 4 121 Other 3 — — — 31 34 Revenues from contracts with customers $ 527 $ 503 $ 203 $ 121 $ 78 $ 1,432 International (E.G.) Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Crude oil and condensate $ 58 $ 20 $ 95 $ 65 Natural gas liquids 1 1 2 2 Natural gas 5 7 12 15 Other 1 — 1 — Revenues from contracts with customers $ 65 $ 28 $ 110 $ 82

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
Segment Information	Segment Information We have two reportable operating segments. Both of these segments are organized and managed based upon geographic location and the nature of the products and services offered. • United States (“U.S.”) – explores for, produces and markets crude oil and condensate, NGLs and natural gas in the United States • International (“Int’l”) – explores for, produces and markets crude oil and condensate, NGLs and natural gas outside of the United States as well as produces and markets products manufactured from natural gas, such as LNG and methanol, in Equatorial Guinea (“E.G.”) Segment income represents income that excludes certain items not allocated to our operating segments, net of income taxes. A portion of our corporate and operations general and administrative support costs are not allocated to the operating segments. These unallocated costs primarily consist of employment costs (including pension effects), professional services, facilities and other costs associated with corporate and operations support activities. Additionally, items which affect comparability such as: gains or losses on dispositions, impairments of proved and certain unproved properties, goodwill, and equity method investments, unrealized gains or losses on commodity and interest rate derivative instruments, effects of pension settlements and curtailments or other items (as determined by the chief operating decision maker (“CODM”)) are not allocated to operating segments. Three Months Ended June 30, 2021 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 1,189 $ 65 $ — $ 1,254 Net gain (loss) on commodity derivatives (91) — (75) (b) (166) Income (loss) from equity method investments — 49 — 49 Net gain on disposal of assets — — 1 1 Other income 3 2 — 5 Less costs and expenses: Production 113 13 — 126 Shipping, handling and other operating 153 2 12 167 Exploration 18 — 7 25 Depreciation, depletion and amortization 506 18 8 532 Impairments — — 46 (c) 46 Taxes other than income 76 — (2) 74 General and administrative 27 4 37 68 Net interest and other — — 59 (d) 59 Other net periodic benefit costs — — 1 1 Loss on early extinguishment of debt — — 19 (e) 19 Income tax provision (benefit) 1 11 (2) 10 Segment income (loss) $ 207 $ 68 $ (259) $ 16 Total assets $ 15,747 $ 1,047 $ 1,006 $ 17,800 Capital expenditures (a) $ 284 $ 2 $ 3 $ 289 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 14 ). (c) Includes impairments of $24 million associated with central facilities in Eagle Ford (See Note 10 ) and $22 million associated with decommissioning costs for non-producing long-lived assets in the Gulf of Mexico (‘GOM’) (See N ot e 1 0 , Note 11 , and Note 23 ). (d) Includes a $22 million loss on 2022 interest rate swaps and a $31 million gain on 2025 interest rate swaps, neither of which were designated as cash flow hedges as of June 30 (See Note 14 ). (e) Represents costs related to a make-whole provision premium and the write off of unamortized discount and issuance costs related to the redemption of the 2022 Notes in April 2021 (See Note 16 ) . Three Months Ended June 30, 2020 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 462 $ 28 $ — $ 490 Net gain (loss) on commodity derivatives 26 — (96) (b) (70) Income (loss) from equity method investments — — (152) (c) (152) Net loss on disposal of assets — — (2) (2) Other income 3 2 1 6 Less costs and expenses: Production 114 15 — 129 Shipping, handling and other operating 91 1 13 105 Exploration 26 — — 26 Depreciation, depletion and amortization 569 22 6 597 Taxes other than income 30 — — 30 General and administrative 32 3 53 (d) 88 Net interest and other — — 69 69 Other net periodic benefit costs — — (7) (e) (7) Income tax benefit (6) (5) (4) (15) Segment loss $ (365) $ (6) $ (379) $ (750) Total assets $ 16,791 $ 1,144 $ 632 $ 18,567 Capital expenditures (a) $ 137 $ — $ 2 $ 139 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 14 ). (c) Partial impairment of investment in equity method investee (See Note 22 ). (d) Includes severance expense associated with workforce reductions of $13 million. (e) Includes pension settlement loss of $14 million and pension curtailment gain of $17 million (See Note 19 ). Six Months Ended June 30, 2021 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 2,321 $ 110 $ — $ 2,431 Net loss on commodity derivatives (162) — (157) (b) (319) Income (loss) from equity method investments — 93 — 93 Net gain on disposal of assets — — 1 1 Other income 4 3 1 8 Less costs and expenses: Production 224 23 — 247 Shipping, handling and other operating 297 6 16 319 Exploration 39 — 7 46 Depreciation, depletion and amortization 978 37 13 1,028 Impairments — — 47 (c) 47 Taxes other than income 150 — (2) 148 General and administrative 50 6 101 (d) 157 Net interest and other — — 72 (e) 72 Other net periodic benefit credit — — (2) (2) Loss on early extinguishment of debt — — 19 (f) 19 Income tax provision (benefit) 6 16 (2) 20 Segment income (loss) $ 419 $ 118 $ (424) $ 113 Total assets $ 15,747 $ 1,047 $ 1,006 $ 17,800 Capital expenditures (a) $ 467 $ 2 $ 4 $ 473 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 14 ). (c) Includes second quarter 2021 impairments of $24 million for central facilities in Eagle Ford (See Note 10 ) and $22 million associated with decommissioning costs for non-producing long-lived assets in GOM (See Note 10 , Note 11 , and Note 23 ). (d) Includes $13 million associated with the termination of an aircraft lease agreement and $12 million arising from severance expenses associated with a workforce reduction. (e) Includes a $19 million gain on 2022 interest rate swaps and a $31 million gain on 2025 interest rate swaps, neither of which were designated as cash flow hedges as of June 30 (See Note 14 ). (f) Represents costs related to a make-whole provision premium and the write off of unamortized discount and issuance costs in regards to the redemption of the 2022 Notes in April 2021 (See Note 16 ). Six Months Ended June 30, 2020 (In millions) U.S. Int’l Not Allocated to Segments Total Revenue from contracts with customers $ 1,432 $ 82 $ — $ 1,514 Net gain on commodity derivatives 57 — 75 (b) 132 Loss from equity method investments — (12) (152) (c) (164) Net gain on disposal of assets — — 7 7 Other income 7 4 2 13 Less costs and expenses: Production 257 32 — 289 Shipping, handling and other operating 231 4 14 249 Exploration 54 — — 54 Depreciation, depletion and amortization 1,186 43 12 1,241 Impairments — — 97 (d) 97 Taxes other than income 96 — — 96 General and administrative 64 7 93 (e) 164 Net interest and other — — 133 133 Other net periodic benefit credit — — (7) (f) (7) Income tax benefit (7) (5) (6) (18) Segment loss $ (385) $ (7) $ (404) $ (796) Total assets $ 16,791 $ 1,144 $ 632 $ 18,567 Capital expenditures (a) $ 698 $ — $ 9 $ 707 (a) Includes accruals. (b) Unrealized gain on commodity derivative instruments (See Note 14 ). (c) Partial impairment of investment in equity method investee (See Note 22 ). (d) Includes the full impairment of the International reporting unit goodwill of $95 million (See Note 13 ). (e) Includes severance expenses associated with workforce reductions of $13 million. (f) Includes pension settlement loss of $16 million and pension curtailment gain of $17 million (See Note 19 ).

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Effective Tax Rate The effective income tax rate is influenced by a variety of factors including the geographic and functional sources of income and the relative magnitude of these sources of income. The difference between the total provision and the sum of the amounts allocated to segments is reported in the “Not Allocated to Segments” column of the tables in Note 5 . For the three and six months ended June 30, 2021 and 2020, our effective income tax rates were as follows: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Effective income tax rate 38 % 2 % 15 % 2 % Our effective income tax rate was different from our U.S. statutory tax rate of 21% for the three and six months ended June 30, 2021 and 2020 as a result of the income mix of our U.S. and E.G. operations, including the income mix within E.G. between equity method investees and subsidiaries. We currently have a full valuation allowance on net federal deferred tax assets in the U.S., which results in no federal deferred tax expense or benefit on current year U.S. activity.

Credit Losses

Credit Losses	6 Months Ended
	Jun. 30, 2021
Credit Loss [Abstract]
Credit Losses	Credit Losses The majority of our receivables are from purchasers of commodities or joint interest owners in properties we operate, both of which are recorded at estimated or invoiced amounts and do not bear interest. The majority of these receivables have payment terms of 30 days or less. At the end of each reporting period, we assess the collectability of our receivables and estimate the expected credit losses using historical data, current market conditions, reasonable and supportable forecasts of future economic conditions and other data as deemed appropriate. Changes in the allowance for doubtful accounts balance were as follows: (In millions) June 30, 2021 December 31, 2020 Beginning balance as of January 1 $ 22 $ 11 Cumulative-effect adjustment — 12 Current period provision (a) (2) 22 Current period write offs (1) (13) Recoveries of amounts previously reserved — (10) Ending balance $ 19 $ 22

Inventories

Inventories	6 Months Ended
	Jun. 30, 2021
Inventory Disclosure [Abstract]
Inventories	Inventories Crude oil and natural gas are recorded at weighted average cost and carried at the lower of cost or net realizable value. Supplies and other items consist principally of tubular goods and equipment which are valued at weighted average cost and reviewed periodically for obsolescence or impairment when market conditions indicate. (In millions) June 30, 2021 December 31, 2020 Crude oil and natural gas $ 12 $ 10 Supplies and other items 66 66 Inventories $ 78 $ 76

Property, Plant and Equipment

Property, Plant and Equipment	6 Months Ended
	Jun. 30, 2021
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment (In millions) June 30, 2021 December 31, 2020 United States $ 14,583 $ 15,156 International 380 414 Corporate 56 68 Net property, plant and equipment $ 15,019 $ 15,638 As of June 30, 2021 and December 31, 2020, we had $158 million and $98 million , respectively, of e xploratory well costs capitalized greater than one year related to suspended wells. Management believes these wells exhibit sufficient quantities of hydrocarbons to justify potential development. The vast majority of the suspended wells require completion activities and installation of infrastructure in order to classify the reserves as proved.

Impairments

Impairments	6 Months Ended
	Jun. 30, 2021
Impairment Expense [Abstract]
Impairments	Impairments The following table summarizes impairment charges of proved properties, goodwill and equity method investments and their corresponding fair values. Three Months Ended June 30, 2021 2020 (In millions) Fair Value Impairment Fair Value Impairment Long-lived assets held for use $ — $ 24 $ — $ — Asset retirement costs of long-lived assets — 22 — — Equity method investment $ — $ — $ 142 $ 152 Six Months Ended June 30, 2021 2020 (In millions) Fair Value Impairment Fair Value Impairment Long-lived assets held for use $ — $ 25 $ — $ 2 Asset retirement costs of long-lived assets — 22 — — Goodwill — — — 95 Equity method investment $ — $ — $ 142 $ 152 • 2021 – During the second quarter of 2021, we recorded an impairment expense of $24 million associated with two central facilities located in Eagle Ford. Decommissioning activities commenced during the quarter, which included the re-routing of existing wells. We also recognized an incremental $22 million of impairment expense associated with an increase in the estimated future decommissioning costs of certain non-producing wells, pipelines and production facilities for previously divested offshore assets located in the Gulf of Mexico. In a prior reporting period, we recorded a $7 million liability in our consolidated balance sheet associated with these assets, thereby increasing the total recognized asset retirement obligation to $29 million as of June 30, 2021. See Note 11 and Note 23 for further information. The combined effects of these items were recorded within the Impairments line item within our consolidated statements of income. • 2020 – During the second quarter of 2020, the continuation of the depressed commodity prices caused us to perform a review of our equity method investments. Our review concluded that a loss of our investment value in one of our equity method investees was other than temporary. As a result, we recorded an impairment of $152 million, which was recognized in income (loss) from equity method investments in our consolidated statements of income. The impairment caused us to incur a basis differential between the net book value of our investment and the amount of our underlying share of equity in the investee’s net assets. This differential is being accreted into income over the remaining useful life of the investee’s primary assets. Additionally, impairments for the first six months of 2020 included $95 million of goodwill impairment in the International reporting unit. See Note 13

Asset Retirement Obligations

Asset Retirement Obligations	6 Months Ended
	Jun. 30, 2021
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	Asset Retirement Obligations Asset retirement obligations primarily consist of estimated costs to remove, dismantle and restore land or seabed at the end of oil and gas production operations. Changes in asset retirement obligations were as follows: June 30, (In millions) 2021 2020 Beginning balance as of January 1 $ 254 $ 255 Incurred liabilities, including acquisitions 6 2 Settled liabilities, including dispositions (2) (3) Accretion expense (included in depreciation, depletion and amortization) 6 6 Revisions of estimates 32 (8) Ending balance as of June 30, total $ 296 $ 252 Ending balance as of June 30, short-term $ 24 $ 10 In the second quarter of 2021, we had a revision of estimate of $29 million related to anticipated costs for decommissioning certain wells, pipelines and production facilities for previously divested offshore non-producing long-lived assets located in the Gulf of Mexico. As of June 30, 2021, $14 million of this revision of estimate was classified as short-term. See Note 23 for further information. During the quarter, we recognized $22 million of impairment expense associated with these non-producing long-lived assets within our consolidated statement of operations. See Note 10 for further information.

Leases

Leases	6 Months Ended
	Jun. 30, 2021
Leases [Abstract]
Leases	Leases We enter into various lease agreements to support our operations including drilling rigs, well fracturing equipment, compressors, buildings, aircraft, vessels, vehicles and miscellaneous field equipment. We primarily act as a lessee in these transactions and the majority of our existing leases are classified as either short-term or long-term operating leases. Supplemental balance sheet information related to leases was as follows: (In millions) June 30, 2021 December 31, 2020 Operating Leases: Balance Sheet Location: Right-of-use asset Other noncurrent assets $ 92 $ 133 Current portion of long-term lease liability Other current liabilities $ 52 $ 70 Long-term lease liability Deferred credits and other liabilities $ 44 $ 67 Our wholly owned subsidiary, Marathon E.G. Production Limited, is a lessor for residential housing in E.G., which is occupied by EGHoldings, a related party equity method investee – see Note 22 . The lease was classified as an operating lease and expires in 2024, with a lessee option to extend through 2034. Lease payments are fixed for the entire duration of the agreement at approximately $6 million per year. Our lease income is reported in other income in our consolidated statements of income for all periods presented. The undiscounted cash flows to be received under this lease agreement are summarized below. (In millions) Operating Lease Future Cash Receipts 2021 $ 4 2022 6 2023 6 2024 6 2025 6 Thereafter 54 Total undiscounted cash flows $ 82 In 2018, we signed an agreement with an owner/lessor to construct and lease a new build-to-suit office building in Houston, Texas . The lessor and other participants are providing financing for up to $340 million to fund the estimated project costs.
Leases	Leases We enter into various lease agreements to support our operations including drilling rigs, well fracturing equipment, compressors, buildings, aircraft, vessels, vehicles and miscellaneous field equipment. We primarily act as a lessee in these transactions and the majority of our existing leases are classified as either short-term or long-term operating leases. Supplemental balance sheet information related to leases was as follows: (In millions) June 30, 2021 December 31, 2020 Operating Leases: Balance Sheet Location: Right-of-use asset Other noncurrent assets $ 92 $ 133 Current portion of long-term lease liability Other current liabilities $ 52 $ 70 Long-term lease liability Deferred credits and other liabilities $ 44 $ 67 Our wholly owned subsidiary, Marathon E.G. Production Limited, is a lessor for residential housing in E.G., which is occupied by EGHoldings, a related party equity method investee – see Note 22 . The lease was classified as an operating lease and expires in 2024, with a lessee option to extend through 2034. Lease payments are fixed for the entire duration of the agreement at approximately $6 million per year. Our lease income is reported in other income in our consolidated statements of income for all periods presented. The undiscounted cash flows to be received under this lease agreement are summarized below. (In millions) Operating Lease Future Cash Receipts 2021 $ 4 2022 6 2023 6 2024 6 2025 6 Thereafter 54 Total undiscounted cash flows $ 82 In 2018, we signed an agreement with an owner/lessor to construct and lease a new build-to-suit office building in Houston, Texas . The lessor and other participants are providing financing for up to $340 million to fund the estimated project costs.

Goodwill

Goodwill	6 Months Ended
	Jun. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill Goodwill is tested for impairment on an annual basis, or between annual tests when events or changes in circumstances indicate the fair value of a reporting unit with goodwill may have been reduced below its carrying value. During the first quarter of 2020, a global pandemic caused a substantial deterioration in the worldwide demand of hydrocarbons. The commensurate decline in our market capitalization indicated that it was more likely than not that the fair value of the International reporting unit was less than its carrying value. We estimated the fair value of our International reporting unit using a combination of market and income approaches. The market approach referenced observable inputs specific to us and our industry, such as the price of our common equity, our enterprise value and valuation multiples of us and peers from the investor analyst community. The income approach utilized discounted cash flows, which were based on forecasted assumptions. These valuation methodologies represent Level 3 fair value measurements. Based on the results, we concluded our goodwill was fully impaired, and recorded an impairment of $95 million in the consolidated statements of income for the first quarter of 2020. This represented the entirety of our goodwill on our consolidated balance sheet.

Derivatives

Derivatives	6 Months Ended
	Jun. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives For further information regarding the fair value measurement of derivative instruments, see Note 15 . All of our commodity derivatives are subject to enforceable master netting arrangements or similar agreements under which we report net amounts. The following tables present the gross fair values of derivative instruments and the reported net amounts along with where they appear on the consolidated balance sheets. June 30, 2021 (In millions) Asset Liability Net Asset (Liability) Balance Sheet Location Not Designated as Hedges Commodity $ — $ 181 $ (181) Other current liabilities Interest Rate 63 — 63 Other noncurrent assets Interest Rate — 1 (1) Deferred credits and other liabilities Total Not Designated as Hedges $ 63 $ 182 $ (119) Cash Flow Hedges Interest Rate $ — $ 2 $ (2) Other current liabilities Interest Rate — 6 (6) Deferred credits and other liabilities Total Designated Hedges $ — $ 8 $ (8) Total $ 63 $ 190 $ (127) December 31, 2020 (In millions) Asset Liability Net Asset (Liability) Balance Sheet Location Not Designated as Hedges Commodity $ 3 $ 1 $ 2 Other current assets Commodity 7 32 (25) Other current liabilities Interest Rate 10 — 10 Other noncurrent assets Total Not Designated as Hedges $ 20 $ 33 $ (13) Cash Flow Hedges Interest Rate $ 19 $ — $ 19 Other noncurrent assets Interest Rate — 16 (16) Deferred credits and other liabilities Total Designated Hedges $ 19 $ 16 $ 3 Total $ 39 $ 49 $ (10) Derivatives Not Designated as Hedges Commodity Derivatives We have entered into multiple crude oil, natural gas and NGL derivatives indexed to the respective indices as noted in the table below, related to a portion of our forecasted U.S. sales through 2022. These derivatives consist of three-way collars, two-way collars, fixed price swaps, basis swaps and NYMEX roll basis swaps. Three-way collars consist of a sold call (ceiling), a purchased put (floor) and a sold put. The ceiling price is the maximum we will receive for the contract volumes; the floor is the minimum price we will receive, unless the market price falls below the sold put strike price. In this case, we receive the NYMEX WTI price plus the difference between the floor and the sold put price. Two-way collars only consist of a sold call (ceiling) and a purchased put (floor). The following table sets forth outstanding derivative contracts as of June 30, 2021, and the weighted average prices for those contracts: 2021 2022 Third Quarter Fourth Quarter First Half Second Half Crude Oil NYMEX WTI Three-Way Collars Volume (Bbls/day) 40,000 40,000 10,000 — Weighted average price per Bbl: Ceiling $ 74.07 $ 78.05 $ 87.84 $ — Floor $ 48.75 $ 50.00 $ 50.00 $ — Sold put $ 38.75 $ 40.00 $ 40.00 $ — NYMEX WTI Two-Way Collars Volume (Bbls/day) 40,000 40,000 — — Weighted average price per Bbl: Ceiling $ 59.41 $ 58.92 $ — $ — Floor $ 39.25 $ 39.25 $ — $ — NYMEX Roll Basis Swaps Volume (Bbls/day) — — 45,000 45,000 Weighted average price per Bbl $ — $ — $ 0.56 $ 0.56 Natural Gas Henry Hub (“HH”) Two-Way Collars Volume (MMBtu/day) 200,000 200,000 — — Weighted average price per MMBtu: Ceiling $ 3.05 $ 3.05 $ — $ — Floor $ 2.50 $ 2.50 $ — $ — HH Fixed Price Swaps Volume (MMBtu/day) 50,000 50,000 — — Weighted average price per MMBtu $ 2.88 $ 2.88 $ — $ — NGL Fixed Price Propane Swaps (a) Volume (Bbls/day) 5,000 5,000 — — Weighted average price per Bbl $ 10.92 $ 10.92 $ — $ — Fixed Price Propane Swaps (b) Volume (Bbls/day) 5,000 5,000 — — Weighted average price per Bbl $ 23.19 $ 23.19 $ — $ — (a) The fixed price ethane swap is priced at OPIS Mont Belvieu Purity Ethane. (b) The fixed price propane swap is priced at OPIS Mont Belvieu Non-TET Propane. The unrealized and realized gain (loss) impact of our commodity derivative instruments appears in the table below and is reflected in net gain (loss) on commodity derivatives in the consolidated statements of income. Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Unrealized gain (loss) on derivative instruments, net $ (75) $ (96) $ (157) $ 75 Realized gain (loss) on derivative instruments, net (a) $ (91) $ 26 $ (162) $ 57 (a) During the second quarter and first six months of 2021, net cash paid for settled derivative positions was $84 million and $95 million, respectively. During the second quarter and first six months of 2020, net cash received for settled derivative positions was $78 million and $91 million, respectively. Interest Rate Swaps During 2020, we entered into forward starting interest rate swaps to hedge the variations in cash flows related to fluctuations in the London Interbank Offered Rate (“LIBOR”) benchmark interest rate related to forecasted interest payments of a future d ebt issuance in 2022. Each respective derivative contract can be tied to an anticipated underlying dollar notional amount. During the third quarter of 2020, we de-designated these forward starting interest rate swaps previously designated as cash flow hedges. In the first quarter of 2021, the net deferred loss of $2 million in accumulated other comprehensive income related to these de-designated forward starting interest rate swaps was reclassified from accumulated other comprehensive income into earnings as an adjustment to net interest, as we fully redeemed the remainder of our outstanding 2022 notes in April 2021. Additionally, we recorded a $22 million mark-to-market loss and a $19 million mark-to-market gain within net interest to reflect the change in value of these interest rate swaps during the three and six months ended June 30, 2021, respectively. During 2020, we entered into forward starting interest rate swaps with a notional amount of $350 million to hedge variations in cash flows arising from fluctuations in the LIBOR benchmark interest rate related to forecasted interest payments of a future debt issuance in 2025. The expected proceeds of the future debt issuance were intended to refinance the $900 million 3.85% Senior Notes due 2025 (“2025 Notes”). During the second quarter of 2021, we de-designated these forward starting interest rate swaps previously designated as cash flow hedges because we no longer plan to refinance the 2025 Notes. In August 2021, we sent an irrevocable notice of redemption to the trustee to fully redeem the 2025 Notes. See Note 16 for further details. We reclassified the $31 million cumulative gain related to these hedges from accumulated other comprehensive income into earnings as an adjustment to net interest. In addition, during the second quarter of 2021, we de-designated $25 million of the $320 million Houston office cash flow hedges (discussed further in the Derivatives Designated as Cash Flow Hedges section below), as the construction cost budget estimate was reduced. The $1 million loss of these de-designated cash flow hedges as of June 30, 2021 was reclassified from accumulated other comprehensive income into earnings as an adjustment to net interest. The following table presents, by maturity date, information about our de-designated forward starting interest rate swap agreements, including the rate. June 30, 2021 December 31, 2020 Maturity Date Aggregate Notional Amount (in millions) Weighted Average, LIBOR Aggregate Notional Amount (in millions) Weighted Average, LIBOR November 1, 2022 $ 500 0.99 % $ 500 0.99 % June 1, 2025 $ 350 0.95 % N/A N/A September 9, 2026 $ 25 1.45 % N/A N/A Derivatives Designated as Cash Flow Hedges During 2019, we entered into forward starting interest rate swaps with a total notional amount of $320 million to hedge variations in cash flows related to the 1-month LIBOR component of future lease payments of our future Houston office. These swaps will settle monthly on the same day the lease payment is made with the first swap settlement occurring in January 2022. D uring the second quarter of 2021, we de-designated $25 million of these hedges as the construction cost budget estimate associated with the project was reduced. The last swap will mature in September 2026. As of June 30, 2021, amounts expected to be reclassified from accumulated other comprehensive income over the next twelve months were not material. See Note 12 for further details regarding the lease of the new Houston office. The following table presents, by maturity date, information about our interest rate swap agreements, including the weighted average LIBOR-based, fixed rate. June 30, 2021 December 31, 2020 Maturity Date Aggregate Notional Amount (in millions) Weighted Average, LIBOR Aggregate Notional Amount (in millions) Weighted Average, LIBOR June 1, 2025 N/A N/A $ 350 0.95 % September 9, 2026 $ 295 1.52 % $ 320 1.51 %

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair Values – Recurring The following tables present assets and liabilities accounted for at fair value on a recurring basis as of June 30, 2021 and December 31, 2020 by hierarchy level. June 30, 2021 (In millions) Level 1 Level 2 Level 3 Total Derivative instruments, assets Interest rate - not designated as cash flow hedges $ — $ 62 $ — $ 62 Derivative instruments, assets $ — $ 62 $ — $ 62 Derivative instruments, liabilities Commodity (a) $ (30) $ (151) $ — $ (181) Interest rate - designated as cash flow hedges — (8) — (8) Derivative instruments, liabilities $ (30) $ (159) $ — $ (189) Total $ (30) $ (97) $ — $ (127) December 31, 2020 (In millions) Level 1 Level 2 Level 3 Total Derivative instruments, assets Interest rate - not designated as cash flow hedges $ — $ 10 $ — $ 10 Interest rate - designated as cash flow hedges — 19 — 19 Derivative instruments, assets $ — $ 29 $ — $ 29 Derivative instruments, liabilities Commodity (a) $ — $ (23) $ — $ (23) Interest rate - designated as cash flow hedges — (16) — (16) Derivative instruments, liabilities $ — $ (39) $ — $ (39) Total $ — $ (10) $ — $ (10) (a) Commodity derivative instruments are recorded on a net basis in our consolidated balance sheet. See Note 14 . Commodity derivatives include three-way collars, two-way collars, fixed price swaps, basis swaps and NYMEX roll basis swaps. These instruments are measured at fair value using either a Black-Scholes or a modified Black-Scholes Model. For swaps, inputs to the models include only commodity prices and interest rates and are categorized as Level 1 because all assumptions and inputs are observable in active markets throughout the term of the instruments. For three-way collars and two-way collars, inputs to the models include commodity prices and implied volatility and are categorized as Level 2 because predominantly all assumptions and inputs are observable in active markets throughout the term of the instruments. The forward starting interest rate swaps are measured at fair value with a market approach using actionable broker quotes, which are Level 2 inputs. See Note 14 for detail on the forward starting interest rate swaps. Fair Value Estimates – Goodwill See Note 13 for detail information relating to goodwill. Fair Values – Nonrecurring See Note 10 for detail on our fair values related to impairments. Fair Values – Financial Instruments Our current assets and liabilities include financial instruments, the most significant of which are receivables, the current portion of our long-term debt and payables. We believe the carrying values of our receivables and payables approximate fair value. Our fair value assessment incorporates a variety of considerations, including (1) the short-term duration of the instruments, (2) our credit rating and (3) our historical incurrence of and expected future insignificant bad debt expense, which includes an evaluation of counterparty credit risk. The following table summarizes financial instruments, excluding receivables, payables and derivative financial instruments, and their reported fair values by individual balance sheet line item at June 30, 2021 and December 31, 2020. June 30, 2021 December 31, 2020 (In millions) Fair Value Carrying Amount Fair Value Carrying Amount Financial assets Current assets $ 13 $ 12 $ 4 $ 4 Other noncurrent assets 12 27 24 37 Total financial assets $ 25 $ 39 $ 28 $ 41 Financial liabilities Current liabilities $ 93 $ 124 $ 72 $ 103 Long-term debt, including current portion (a) 5,735 4,931 6,077 5,431 Deferred credits and other liabilities 69 50 103 76 Total financial liabilities $ 5,897 $ 5,105 $ 6,252 $ 5,610 (a) Excludes debt issuance costs. Fair values of our financial assets included in other noncurrent assets, and of our financial liabilities included in other current liabilities and deferred credits and other liabilities, are measured using an income approach and most inputs are internally generated, which results in a Level 3 classification. Estimated future cash flows are discounted using a rate deemed appropriate to obtain the fair value.

Debt

Debt	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Debt	Debt Revolving Credit Facility On June 21, 2021, we executed the sixth amendment to our unsecured revolving credit facility (“Credit Facility”). The primary changes resulting from this amendment are (i) increasing the size of the Credit Facility from $3.0 billion to $3.1 billion, (ii) extending the maturity of the commitments of certain consenting lenders from May 28, 2023 to June 21, 2024 (with the remaining commitment of a single non-consenting lender to mature on May 28, 2023, at which time the size of the Credit Facility will be reduced to $3.0 billion) and (iii) including certain other provisions and revisions, including provisions to provide for the eventual replacement of LIBOR as a benchmark interest rate. As of June 30, 2021, we had no borrowings against our Credit Facility. The Credit Facility includes a covenant requiring our total debt to total capitalization ratio not to exceed 65% as of the last day of each fiscal quarter. In the event of a default, the lenders holding more than half of the commitments may terminate the commitments under the Credit Facility and require the immediate repayment of all outstanding borrowings and the cash collateralization of all outstanding letters of credit under the Credit Facility. As of June 30, 2021, we were in compliance with this covenant with a ratio of 24%. Debt Redemption On March 30, 2021, we sent an irrevocable notice of redemption to the trustee to fully redeem our outstanding $500 million 2.8% Senior Notes due 2022 (“2022 Notes”). The 2022 Notes were redeemed on April 29, 2021 and as a result of the settlement, we incurred $19 million in costs related to a make-whole provision premium and the write off of unamortized discount and issuance costs. Long-term debt

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Stockholders' Equity	Stockholders’ EquityNo share repurchases were made under our share repurchases program during the six months ended June 30, 2021; however, we repurchased $9 million of shares during the first quarter related to our tax withholding obligation associated with the vesting of employee restricted stock awards. The total remaining share repurchase authorization was $1.3 billion at June 30, 2021. Purchases under the program are made at our discretion and may be in either open market transactions, including block purchases, or in privately negotiated transactions using cash on hand, cash generated from operations, or proceeds from potential asset sales. This program may be changed based upon our financial condition or changes in market conditions and is subject to termination prior to completion.

Incentive Based Compensation

Incentive Based Compensation	6 Months Ended
	Jun. 30, 2021
Share-based Payment Arrangement [Abstract]
Incentive Based Compensation	Incentive Based Compensation Stock options, restricted stock awards and restricted stock units The following table presents a summary of activity for the first six months of 2021: Stock Options Restricted Stock Awards & Units Number of Shares Weighted Average Exercise Price Awards Weighted Average Grant Date Fair Value Outstanding at December 31, 2020 6,014,255 $ 21.00 7,851,754 $ 11.72 Granted — $ — 2,297,929 $ 11.20 Exercised/Vested (384,889) $ 7.34 (2,896,748) $ 12.56 Canceled (a) (1,106,590) $ 22.82 (893,808) $ 11.97 Outstanding at June 30, 2021 4,522,776 $ 21.72 6,359,127 $ 11.12 (a) Included in canceled are forfeitures related to workforce reductions. Stock-based performance unit awards During the first six months of 2021, we granted 307,473 stock-based performance units to eligible officers, which are settled in shares. The grant date fair value per unit was $18.07, as calculated using a Monte Carlo valuation model. At the grant date, each unit represents the value of one share of our common stock. These units are settled in shares, and the number of shares of our common stock to be paid is based on the vesting percentage, which can be from zero to 200% based on performance achieved during the performance period and as determined by the Compensation Committee of the Board of Directors (“Compensation Committee”). The performance goals are tied to our total shareholder return (“TSR”) as compared to TSR for a group including peer companies, the S&P Energy Index and the S&P 500 Index, which is determined by the Compensation Committee. Also, dividend equivalents accrue during the performance period and would be paid in cash following the end of the performance period based on the amount of dividends credited on shares of our common stock over the performance period multiplied by the number of units that vest. During the first six months of 2021, we introduced a new type of stock-based performance unit award under the Marathon Oil Corporation 2019 Incentive Compensation Plan and granted 307,473 units to eligible officers, which are settled in cash. At the grant date for these new stock-based performance units, each unit represents the value of one share of our common stock. The benefit amount to be paid is based on the product of (i) the number of units granted, (ii) the vesting percentage, and (iii) the average daily closing price of our common stock during the final 30 calendar days ending on the last trading day of the

Defined Benefit Postretirement

Defined Benefit Postretirement Plans	6 Months Ended
	Jun. 30, 2021
Retirement Benefits [Abstract]
Defined Benefit Postretirement Plans	Defined Benefit Postretirement Plans The following summarizes the components of net periodic benefit costs (credits): Three Months Ended June 30, Pension Benefits Other Benefits (In millions) 2021 2020 2021 2020 Service cost $ 4 $ 5 $ — $ — Interest cost 2 2 1 — Expected return on plan assets (2) (2) — — Amortization: – prior service credit (1) (2) (4) (5) – actuarial loss 1 2 — 1 Net settlement loss (a) 5 14 — — Net curtailment gain (b) — (3) — (14) Net periodic benefit costs (credits) (c) $ 9 $ 16 $ (3) $ (18) Six Months Ended June 30, Pension Benefits Other Benefits (In millions) 2021 2020 2021 2020 Service cost $ 8 $ 10 $ — $ — Interest cost 4 5 1 1 Expected return on plan assets (4) (5) — — Amortization: – prior service credit (3) (4) (8) (9) – actuarial loss 3 5 1 1 Net settlement loss (a) 5 16 — — Net curtailment gain (b) — (3) — (14) Net periodic benefit costs (credits) (c) $ 13 $ 24 $ (6) $ (21) (a) Settlements are recognized as they occur, once it is probable that lump sum payments from a plan for a given year will exceed the plan’s total service and interest cost for that year. (b) Related to workforce reductions, which reduced the future expected years of service for employees participating in the plans. (c) Net periodic benefit costs (credits) reflects a calculated market-related value of plan assets which recognizes changes in fair value over three years. During the first six months of 2021, we made contributions of $14 million to our funded pension plan. During the first six months of 2021, we also made payments of $2 million and $5 million related to unfunded pension plans and other postretirement benefit plans. We expect to contribute an additional $9 million in contributions to our funded pension plan this year.

Reclassifications Out of Accumu

Reclassifications Out of Accumulated Other Comprehensive Income (Loss)	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)	Reclassifications Out of Accumulated Other Comprehensive Income (Loss) The following table presents a summary of amounts reclassified from accumulated other comprehensive income (loss): Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Income Statement Line Postretirement and postemployment plans Amortization of prior service credit $ 5 $ 7 $ 11 $ 13 Other net periodic benefit costs Amortization of actuarial loss (1) (3) (4) (6) Other net periodic benefit costs Net settlement loss (5) (14) (5) (16) Other net periodic benefit costs Net curtailment gain — 17 — 17 Other net periodic benefit costs Interest rate swaps Reclassification of de-designated forward interest rate swaps (30) — (28) — Net interest and other Total reclassifications of (income) expense, net of tax (a) $ (31) $ 7 $ (26) $ 8 Net income (loss)

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	6 Months Ended
	Jun. 30, 2021
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information Six Months Ended June 30, (In millions) 2021 2020 Included in operating activities: Interest paid, net of amounts capitalized $ 123 $ 126 Income taxes paid to (received from) taxing authorities, net of refunds (a) $ 9 $ 4 Noncash investing activities: Increase (decrease) in asset retirement costs $ 38 $ (6) (a) The six months ended June 30, 2020 includes $4 million related to tax refunds. Other noncash investing activities include accrued capital expenditures for the six months ended June 30, 2021 and 2020 of $85 million and $48 million, respectively.

Equity Method Investments

Equity Method Investments	6 Months Ended
	Jun. 30, 2021
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments During the periods ended June 30, 2021 and December 31, 2020 our equity method investees were considered related parties and are summarized in the following table: (In millions) Ownership as of June 30, 2021 June 30, 2021 December 31, 2020 EGHoldings (a) 60% $ 138 $ 113 Alba Plant LLC (b) 52% 168 168 AMPCO (c) 45% 152 166 Total $ 458 $ 447 (a) EGHoldings is engaged in LNG production activity. (b) Alba Plant LLC processes LPG. (c) AMPCO is engaged in methanol production activity. Summarized financial information for equity method investees is as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Income data: Revenues and other income $ 246 $ 111 $ 481 $ 283 Income (loss) from operations 111 (10) 207 (40) Net income (loss) $ 85 $ (13) $ 157 $ (39) Revenues from related parties were $8 million and $16 million for the three and six months ended June 30, 2021, respectively, and $10 million and $20 million for the three and six months ended 2020, respectively, with the majority related to EGHoldings in all periods.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies In the second quarter of 2019, Marathon E.G. Production Limited (“MEGPL”), a consolidated and wholly owned subsidiary, signed a series of agreements to process third-party Alen Unit gas through existing infrastructure located in Punta Europa, E.G. Our equity method investee, Alba Plant LLC, is also a party to some of the agreements. These agreements require (subject to certain limitations) MEGPL to indemnify the owners of the Alen Unit against injury to Alba Plant LLC’s personnel and damage to or loss of Alba Plant LLC’s automobiles, as well as third party claims caused by Alba Plant LLC and certain environmental liabilities arising from certain hydrocarbons in the custody of Alba Plant LLC. At this time, we cannot reasonably estimate this obligation as we do not have any history of prior indemnification claims or environmental discharge or contamination. Therefore, we have not recorded a liability with respect to these indemnities since the amount of potential future payments under these indemnification clauses is not determinable. The agreements to process the third-party Alen Unit gas required the execution of third-party guarantees by Marathon Oil Corporation in favor of the Alen Unit’s owners. Two separate guarantees were executed during the second quarter of 2020; one for a maximum of approximately $91 million pertaining to the payment obligations of Equatorial Guinea LNG Operations, S.A. and another for a maximum of $25 million pertaining to the payment obligations of Alba Plant LLC. Payment by us would be required if any of those entities fails to honor its payment obligations pursuant to the relevant agreements with the owners of the Alen Unit. Certain owners of the Alen Unit, or their affiliates, are also direct or indirect shareholders in Equatorial Guinea LNG Operations, S.A. and Alba Plant LLC. Each guarantee expires no later than December 31, 2027. We measured these guarantees at fair value using the net present value of premium payments we expect to receive from our investees. Our liability for these guarantees was approximately $4 million as of June 30, 2021, with a corresponding receivable from our investees. Each of Equatorial Guinea LNG Operations, S.A. and Equatorial Guinea LNG Train 1, S.A. provided us with a pledge of its receivables as recourse against any payments we may make under the guaranty of Equatorial Guinea LNG Operations, S.A.’s performance. Various groups, including the State of North Dakota and three Indian tribes represented by the Bureau of Indian Affairs, have been involved in a dispute regarding the ownership of certain lands underlying the Missouri River and Little Missouri River. As a result, as of June 30, 2021, we have a $121 million current liability in suspended royalty and working interest revenue, including interest, of which $111 million was included within accounts payable and $10 million related to accrued interest and was included within other current liabilities on our consolidated balance sheet. Additionally, we have a long-term receivable of $24 million for capital and expenses. In January 2020, we received a Notice of Violation from the EPA related to the Clean Air Act. The enforcement action will likely result in monetary sanctions and corrective actions yet-to-be specified and, while the ultimate outcome and impact to us cannot be predicted with certainty, we believe these enforcement actions will not have a material adverse effect on our consolidated financial position, results of operations or cash flows. We are a defendant in a number of legal and administrative proceedings arising in the ordinary course of business including, but not limited to, royalty claims, contract claims, tax disputes and environmental claims. While the ultimate outcome and impact to us cannot be predicted with certainty, we believe the resolution of these proceedings will not have a material adverse effect on our consolidated financial position, results of operations or cash flows. In addition, we may also be subject to retained liabilities with respect to certain divested assets by operation of law. For example, declines in commodity prices have created an environment where there is an increased risk that owners and/or operators of assets purchased from us may no longer be able to satisfy plugging or abandonment obligations that attach to those assets. In that event, due to operation of law, we may be required to assume plugging or abandonment obligations for those assets. Although we have established reserves for such liabilities, we could be required to accrue additional amounts in the future and these amounts could be material. For instance, as the result of the declaration of bankruptcy by a third party to which we previously divested certain offshore assets, in the second quarter of 2021 we increased our existing reserve to $29 million related to the anticipated cost to decommission certain wells, pipelines and production facilities divested to such third party. We no longer own these assets nor are they related to our current operations. Marathon Oil has been named in various lawsuits alleging royalty underpayments in our domestic operations, and plaintiffs in some of these lawsuits are seeking class certification. We intend to vigorously defend ourselves against such claims. Although we have accrued for potential liabilities associated with these lawsuits, those accruals are based on currently available information and involve elements of judgment and significant uncertainties. Accordingly, actual losses may exceed our accruals or we could be required to accrue additional amounts in the future and these amounts could be material. We have incurred and will continue to incur capital, operating and maintenance, and remediation expenditures as a result of environmental laws and regulations. If these expenditures, as with all costs, are not ultimately offset by the prices we receive for our products and services, our operating results will be adversely affected. We believe that substantially all of our competitors must comply with similar environmental laws and regulations. However, the specific impact on each competitor may vary depending on a number of factors, including the age and location of its operating facilities, marketing areas and production processes. These laws generally provide for control of pollutants released into the environment and require responsible parties to undertake remediation of hazardous waste disposal sites. Penalties may be imposed for noncompliance. At June 30, 2021, accrued liabilities for remediation relating to environmental laws and regulations were not material. It is not presently possible to estimate the ultimate amount of all remediation cost that might be incurred or the penalties that may be imposed.

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	These consolidated financial statements are unaudited; however, in the opinion of management, these statements reflect all adjustments necessary for a fair statement of the results for the periods reported. All such adjustments are of a normal recurring nature unless disclosed otherwise. These consolidated financial statements, including notes, have been prepared in accordance with the applicable rules of the SEC and do not include all of the information and disclosures required by U.S. GAAP for complete financial statements. These interim financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in our 2020 Annual Report on Form 10-K. The results of operations for the second quarter and first six months of 2021 are not necessarily indicative of the results to be expected for the full year.

Income (loss) and Dividends p_2

Income (loss) and Dividends per Common Share (Tables)	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Schedule of Loss Per Share, Basic and Diluted	The per share calculations below exclude 4 million and 5 million of stock options for each of the three and six months ended June 30, 2021, respectively, and 7 million of stock options for each of the three and six months ended June 30, 2020 that were antidilutive. Three Months Ended June 30, Six Months Ended June 30, (In millions, except per share data) 2021 2020 2021 2020 Net income (loss) $ 16 $ (750) $ 113 $ (796) Weighted average common shares outstanding 789 790 790 793 Effect of dilutive securities — — 1 — Weighted average common shares, diluted 789 790 791 793 Net income (loss) per share: Basic $ 0.02 $ (0.95) $ 0.14 $ (1.00) Diluted $ 0.02 $ (0.95) $ 0.14 $ (1.00) Dividends per share $ 0.04 $ — $ 0.07 $ 0.05

Revenues (Tables)

Revenues (Tables)	6 Months Ended
	Jun. 30, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables present our revenues from contracts with customers disaggregated by product type and geographic areas for the three and six months ended June 30 as follows: United States Three Months Ended June 30, 2021 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 353 $ 411 $ 71 $ 77 $ 24 $ 936 Natural gas liquids 33 48 37 11 2 131 Natural gas 29 17 41 5 (1) 91 Other 2 — — — 29 31 Revenues from contracts with customers $ 417 $ 476 $ 149 $ 93 $ 54 $ 1,189 Three Months Ended June 30, 2020 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 142 $ 147 $ 32 $ 33 $ 7 $ 361 Natural gas liquids 16 3 13 4 1 37 Natural gas 20 5 24 4 1 54 Other 1 — — — 9 10 Revenues from contracts with customers $ 179 $ 155 $ 69 $ 41 $ 18 $ 462 Six Months Ended June 30, 2021 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 612 $ 783 $ 132 $ 154 $ 46 $ 1,727 Natural gas liquids 59 89 74 20 5 247 Natural gas 76 42 150 30 8 306 Other 4 — — — 37 41 Revenues from contracts with customers $ 751 $ 914 $ 356 $ 204 $ 96 $ 2,321 Six Months Ended June 30, 2020 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 449 $ 477 $ 116 $ 107 $ 40 $ 1,189 Natural gas liquids 31 13 34 7 3 88 Natural gas 44 13 53 7 4 121 Other 3 — — — 31 34 Revenues from contracts with customers $ 527 $ 503 $ 203 $ 121 $ 78 $ 1,432 International (E.G.) Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Crude oil and condensate $ 58 $ 20 $ 95 $ 65 Natural gas liquids 1 1 2 2 Natural gas 5 7 12 15 Other 1 — 1 — Revenues from contracts with customers $ 65 $ 28 $ 110 $ 82

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Three Months Ended June 30, 2021 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 1,189 $ 65 $ — $ 1,254 Net gain (loss) on commodity derivatives (91) — (75) (b) (166) Income (loss) from equity method investments — 49 — 49 Net gain on disposal of assets — — 1 1 Other income 3 2 — 5 Less costs and expenses: Production 113 13 — 126 Shipping, handling and other operating 153 2 12 167 Exploration 18 — 7 25 Depreciation, depletion and amortization 506 18 8 532 Impairments — — 46 (c) 46 Taxes other than income 76 — (2) 74 General and administrative 27 4 37 68 Net interest and other — — 59 (d) 59 Other net periodic benefit costs — — 1 1 Loss on early extinguishment of debt — — 19 (e) 19 Income tax provision (benefit) 1 11 (2) 10 Segment income (loss) $ 207 $ 68 $ (259) $ 16 Total assets $ 15,747 $ 1,047 $ 1,006 $ 17,800 Capital expenditures (a) $ 284 $ 2 $ 3 $ 289 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 14 ). (c) Includes impairments of $24 million associated with central facilities in Eagle Ford (See Note 10 ) and $22 million associated with decommissioning costs for non-producing long-lived assets in the Gulf of Mexico (‘GOM’) (See N ot e 1 0 , Note 11 , and Note 23 ). (d) Includes a $22 million loss on 2022 interest rate swaps and a $31 million gain on 2025 interest rate swaps, neither of which were designated as cash flow hedges as of June 30 (See Note 14 ). (e) Represents costs related to a make-whole provision premium and the write off of unamortized discount and issuance costs related to the redemption of the 2022 Notes in April 2021 (See Note 16 ) . Three Months Ended June 30, 2020 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 462 $ 28 $ — $ 490 Net gain (loss) on commodity derivatives 26 — (96) (b) (70) Income (loss) from equity method investments — — (152) (c) (152) Net loss on disposal of assets — — (2) (2) Other income 3 2 1 6 Less costs and expenses: Production 114 15 — 129 Shipping, handling and other operating 91 1 13 105 Exploration 26 — — 26 Depreciation, depletion and amortization 569 22 6 597 Taxes other than income 30 — — 30 General and administrative 32 3 53 (d) 88 Net interest and other — — 69 69 Other net periodic benefit costs — — (7) (e) (7) Income tax benefit (6) (5) (4) (15) Segment loss $ (365) $ (6) $ (379) $ (750) Total assets $ 16,791 $ 1,144 $ 632 $ 18,567 Capital expenditures (a) $ 137 $ — $ 2 $ 139 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 14 ). (c) Partial impairment of investment in equity method investee (See Note 22 ). (d) Includes severance expense associated with workforce reductions of $13 million. (e) Includes pension settlement loss of $14 million and pension curtailment gain of $17 million (See Note 19 ). Six Months Ended June 30, 2021 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 2,321 $ 110 $ — $ 2,431 Net loss on commodity derivatives (162) — (157) (b) (319) Income (loss) from equity method investments — 93 — 93 Net gain on disposal of assets — — 1 1 Other income 4 3 1 8 Less costs and expenses: Production 224 23 — 247 Shipping, handling and other operating 297 6 16 319 Exploration 39 — 7 46 Depreciation, depletion and amortization 978 37 13 1,028 Impairments — — 47 (c) 47 Taxes other than income 150 — (2) 148 General and administrative 50 6 101 (d) 157 Net interest and other — — 72 (e) 72 Other net periodic benefit credit — — (2) (2) Loss on early extinguishment of debt — — 19 (f) 19 Income tax provision (benefit) 6 16 (2) 20 Segment income (loss) $ 419 $ 118 $ (424) $ 113 Total assets $ 15,747 $ 1,047 $ 1,006 $ 17,800 Capital expenditures (a) $ 467 $ 2 $ 4 $ 473 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 14 ). (c) Includes second quarter 2021 impairments of $24 million for central facilities in Eagle Ford (See Note 10 ) and $22 million associated with decommissioning costs for non-producing long-lived assets in GOM (See Note 10 , Note 11 , and Note 23 ). (d) Includes $13 million associated with the termination of an aircraft lease agreement and $12 million arising from severance expenses associated with a workforce reduction. (e) Includes a $19 million gain on 2022 interest rate swaps and a $31 million gain on 2025 interest rate swaps, neither of which were designated as cash flow hedges as of June 30 (See Note 14 ). (f) Represents costs related to a make-whole provision premium and the write off of unamortized discount and issuance costs in regards to the redemption of the 2022 Notes in April 2021 (See Note 16 ). Six Months Ended June 30, 2020 (In millions) U.S. Int’l Not Allocated to Segments Total Revenue from contracts with customers $ 1,432 $ 82 $ — $ 1,514 Net gain on commodity derivatives 57 — 75 (b) 132 Loss from equity method investments — (12) (152) (c) (164) Net gain on disposal of assets — — 7 7 Other income 7 4 2 13 Less costs and expenses: Production 257 32 — 289 Shipping, handling and other operating 231 4 14 249 Exploration 54 — — 54 Depreciation, depletion and amortization 1,186 43 12 1,241 Impairments — — 97 (d) 97 Taxes other than income 96 — — 96 General and administrative 64 7 93 (e) 164 Net interest and other — — 133 133 Other net periodic benefit credit — — (7) (f) (7) Income tax benefit (7) (5) (6) (18) Segment loss $ (385) $ (7) $ (404) $ (796) Total assets $ 16,791 $ 1,144 $ 632 $ 18,567 Capital expenditures (a) $ 698 $ — $ 9 $ 707 (a) Includes accruals. (b) Unrealized gain on commodity derivative instruments (See Note 14 ). (c) Partial impairment of investment in equity method investee (See Note 22 ). (d) Includes the full impairment of the International reporting unit goodwill of $95 million (See Note 13 ). (e) Includes severance expenses associated with workforce reductions of $13 million. (f) Includes pension settlement loss of $16 million and pension curtailment gain of $17 million (See Note 19 ).

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2021
Income Tax Disclosure [Abstract]
Effective Income Tax Rate	For the three and six months ended June 30, 2021 and 2020, our effective income tax rates were as follows: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Effective income tax rate 38 % 2 % 15 % 2 %

Credit Losses (Tables)

Credit Losses (Tables)	6 Months Ended
	Jun. 30, 2021
Credit Loss [Abstract]
Changes in Allowance For Doubtful Account Balance	Changes in the allowance for doubtful accounts balance were as follows: (In millions) June 30, 2021 December 31, 2020 Beginning balance as of January 1 $ 22 $ 11 Cumulative-effect adjustment — 12 Current period provision (a) (2) 22 Current period write offs (1) (13) Recoveries of amounts previously reserved — (10) Ending balance $ 19 $ 22

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 30, 2021
Inventory Disclosure [Abstract]
Schedule of Inventory, Current	(In millions) June 30, 2021 December 31, 2020 Crude oil and natural gas $ 12 $ 10 Supplies and other items 66 66 Inventories $ 78 $ 76

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	6 Months Ended
	Jun. 30, 2021
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	(In millions) June 30, 2021 December 31, 2020 United States $ 14,583 $ 15,156 International 380 414 Corporate 56 68 Net property, plant and equipment $ 15,019 $ 15,638

Impairments (Tables)

Impairments (Tables)	6 Months Ended
	Jun. 30, 2021
Impairment Expense [Abstract]
Fair Value Measurements, Nonrecurring	The following table summarizes impairment charges of proved properties, goodwill and equity method investments and their corresponding fair values. Three Months Ended June 30, 2021 2020 (In millions) Fair Value Impairment Fair Value Impairment Long-lived assets held for use $ — $ 24 $ — $ — Asset retirement costs of long-lived assets — 22 — — Equity method investment $ — $ — $ 142 $ 152 Six Months Ended June 30, 2021 2020 (In millions) Fair Value Impairment Fair Value Impairment Long-lived assets held for use $ — $ 25 $ — $ 2 Asset retirement costs of long-lived assets — 22 — — Goodwill — — — 95 Equity method investment $ — $ — $ 142 $ 152

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	6 Months Ended
	Jun. 30, 2021
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Changes in Asset Retirement Obligations	Asset retirement obligations primarily consist of estimated costs to remove, dismantle and restore land or seabed at the end of oil and gas production operations. Changes in asset retirement obligations were as follows: June 30, (In millions) 2021 2020 Beginning balance as of January 1 $ 254 $ 255 Incurred liabilities, including acquisitions 6 2 Settled liabilities, including dispositions (2) (3) Accretion expense (included in depreciation, depletion and amortization) 6 6 Revisions of estimates 32 (8) Ending balance as of June 30, total $ 296 $ 252 Ending balance as of June 30, short-term $ 24 $ 10

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2021
Leases [Abstract]
Supplemental Balance Sheet Information	Supplemental balance sheet information related to leases was as follows: (In millions) June 30, 2021 December 31, 2020 Operating Leases: Balance Sheet Location: Right-of-use asset Other noncurrent assets $ 92 $ 133 Current portion of long-term lease liability Other current liabilities $ 52 $ 70 Long-term lease liability Deferred credits and other liabilities $ 44 $ 67
Operating Lease, Undiscounted Cash Flows to be Received	The undiscounted cash flows to be received under this lease agreement are summarized below. (In millions) Operating Lease Future Cash Receipts 2021 $ 4 2022 6 2023 6 2024 6 2025 6 Thereafter 54 Total undiscounted cash flows $ 82

Derivatives (Tables)

Derivatives (Tables)	6 Months Ended
	Jun. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in the Consolidated Balance Sheets	The following tables present the gross fair values of derivative instruments and the reported net amounts along with where they appear on the consolidated balance sheets. June 30, 2021 (In millions) Asset Liability Net Asset (Liability) Balance Sheet Location Not Designated as Hedges Commodity $ — $ 181 $ (181) Other current liabilities Interest Rate 63 — 63 Other noncurrent assets Interest Rate — 1 (1) Deferred credits and other liabilities Total Not Designated as Hedges $ 63 $ 182 $ (119) Cash Flow Hedges Interest Rate $ — $ 2 $ (2) Other current liabilities Interest Rate — 6 (6) Deferred credits and other liabilities Total Designated Hedges $ — $ 8 $ (8) Total $ 63 $ 190 $ (127) December 31, 2020 (In millions) Asset Liability Net Asset (Liability) Balance Sheet Location Not Designated as Hedges Commodity $ 3 $ 1 $ 2 Other current assets Commodity 7 32 (25) Other current liabilities Interest Rate 10 — 10 Other noncurrent assets Total Not Designated as Hedges $ 20 $ 33 $ (13) Cash Flow Hedges Interest Rate $ 19 $ — $ 19 Other noncurrent assets Interest Rate — 16 (16) Deferred credits and other liabilities Total Designated Hedges $ 19 $ 16 $ 3 Total $ 39 $ 49 $ (10) The unrealized and realized gain (loss) impact of our commodity derivative instruments appears in the table below and is reflected in net gain (loss) on commodity derivatives in the consolidated statements of income. Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Unrealized gain (loss) on derivative instruments, net $ (75) $ (96) $ (157) $ 75 Realized gain (loss) on derivative instruments, net (a) $ (91) $ 26 $ (162) $ 57 (a) During the second quarter and first six months of 2021, net cash paid for settled derivative positions was $84 million and $95 million, respectively. During the second quarter and first six months of 2020, net cash received for settled derivative positions was $78 million and $91 million, respectively.
Schedule of Notional Amounts of Outstanding Derivative Positions	The following table sets forth outstanding derivative contracts as of June 30, 2021, and the weighted average prices for those contracts: 2021 2022 Third Quarter Fourth Quarter First Half Second Half Crude Oil NYMEX WTI Three-Way Collars Volume (Bbls/day) 40,000 40,000 10,000 — Weighted average price per Bbl: Ceiling $ 74.07 $ 78.05 $ 87.84 $ — Floor $ 48.75 $ 50.00 $ 50.00 $ — Sold put $ 38.75 $ 40.00 $ 40.00 $ — NYMEX WTI Two-Way Collars Volume (Bbls/day) 40,000 40,000 — — Weighted average price per Bbl: Ceiling $ 59.41 $ 58.92 $ — $ — Floor $ 39.25 $ 39.25 $ — $ — NYMEX Roll Basis Swaps Volume (Bbls/day) — — 45,000 45,000 Weighted average price per Bbl $ — $ — $ 0.56 $ 0.56 Natural Gas Henry Hub (“HH”) Two-Way Collars Volume (MMBtu/day) 200,000 200,000 — — Weighted average price per MMBtu: Ceiling $ 3.05 $ 3.05 $ — $ — Floor $ 2.50 $ 2.50 $ — $ — HH Fixed Price Swaps Volume (MMBtu/day) 50,000 50,000 — — Weighted average price per MMBtu $ 2.88 $ 2.88 $ — $ — NGL Fixed Price Propane Swaps (a) Volume (Bbls/day) 5,000 5,000 — — Weighted average price per Bbl $ 10.92 $ 10.92 $ — $ — Fixed Price Propane Swaps (b) Volume (Bbls/day) 5,000 5,000 — — Weighted average price per Bbl $ 23.19 $ 23.19 $ — $ — (a) The fixed price ethane swap is priced at OPIS Mont Belvieu Purity Ethane. (b) The fixed price propane swap is priced at OPIS Mont Belvieu Non-TET Propane.
Schedule of Interest Rate Swap Agreement	The following table presents, by maturity date, information about our de-designated forward starting interest rate swap agreements, including the rate. June 30, 2021 December 31, 2020 Maturity Date Aggregate Notional Amount (in millions) Weighted Average, LIBOR Aggregate Notional Amount (in millions) Weighted Average, LIBOR November 1, 2022 $ 500 0.99 % $ 500 0.99 % June 1, 2025 $ 350 0.95 % N/A N/A September 9, 2026 $ 25 1.45 % N/A N/A The following table presents, by maturity date, information about our interest rate swap agreements, including the weighted average LIBOR-based, fixed rate. June 30, 2021 December 31, 2020 Maturity Date Aggregate Notional Amount (in millions) Weighted Average, LIBOR Aggregate Notional Amount (in millions) Weighted Average, LIBOR June 1, 2025 N/A N/A $ 350 0.95 % September 9, 2026 $ 295 1.52 % $ 320 1.51 %

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following tables present assets and liabilities accounted for at fair value on a recurring basis as of June 30, 2021 and December 31, 2020 by hierarchy level. June 30, 2021 (In millions) Level 1 Level 2 Level 3 Total Derivative instruments, assets Interest rate - not designated as cash flow hedges $ — $ 62 $ — $ 62 Derivative instruments, assets $ — $ 62 $ — $ 62 Derivative instruments, liabilities Commodity (a) $ (30) $ (151) $ — $ (181) Interest rate - designated as cash flow hedges — (8) — (8) Derivative instruments, liabilities $ (30) $ (159) $ — $ (189) Total $ (30) $ (97) $ — $ (127) December 31, 2020 (In millions) Level 1 Level 2 Level 3 Total Derivative instruments, assets Interest rate - not designated as cash flow hedges $ — $ 10 $ — $ 10 Interest rate - designated as cash flow hedges — 19 — 19 Derivative instruments, assets $ — $ 29 $ — $ 29 Derivative instruments, liabilities Commodity (a) $ — $ (23) $ — $ (23) Interest rate - designated as cash flow hedges — (16) — (16) Derivative instruments, liabilities $ — $ (39) $ — $ (39) Total $ — $ (10) $ — $ (10) (a) Commodity derivative instruments are recorded on a net basis in our consolidated balance sheet. See Note 14
Fair Value, by Balance Sheet Grouping	The following table summarizes financial instruments, excluding receivables, payables and derivative financial instruments, and their reported fair values by individual balance sheet line item at June 30, 2021 and December 31, 2020. June 30, 2021 December 31, 2020 (In millions) Fair Value Carrying Amount Fair Value Carrying Amount Financial assets Current assets $ 13 $ 12 $ 4 $ 4 Other noncurrent assets 12 27 24 37 Total financial assets $ 25 $ 39 $ 28 $ 41 Financial liabilities Current liabilities $ 93 $ 124 $ 72 $ 103 Long-term debt, including current portion (a) 5,735 4,931 6,077 5,431 Deferred credits and other liabilities 69 50 103 76 Total financial liabilities $ 5,897 $ 5,105 $ 6,252 $ 5,610

Incentive Based Compensation (T

Incentive Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Stock Options, Restricted Stock Awards and Restricted Stock Units Activity	The following table presents a summary of activity for the first six months of 2021: Stock Options Restricted Stock Awards & Units Number of Shares Weighted Average Exercise Price Awards Weighted Average Grant Date Fair Value Outstanding at December 31, 2020 6,014,255 $ 21.00 7,851,754 $ 11.72 Granted — $ — 2,297,929 $ 11.20 Exercised/Vested (384,889) $ 7.34 (2,896,748) $ 12.56 Canceled (a) (1,106,590) $ 22.82 (893,808) $ 11.97 Outstanding at June 30, 2021 4,522,776 $ 21.72 6,359,127 $ 11.12 (a) Included in canceled are forfeitures related to workforce reductions.

Defined Benefit Postretiremen_2

Defined Benefit Postretirement Plans (Tables)	6 Months Ended
	Jun. 30, 2021
Retirement Benefits [Abstract]
Schedule of Net Periodic Benefit Cost	The following summarizes the components of net periodic benefit costs (credits): Three Months Ended June 30, Pension Benefits Other Benefits (In millions) 2021 2020 2021 2020 Service cost $ 4 $ 5 $ — $ — Interest cost 2 2 1 — Expected return on plan assets (2) (2) — — Amortization: – prior service credit (1) (2) (4) (5) – actuarial loss 1 2 — 1 Net settlement loss (a) 5 14 — — Net curtailment gain (b) — (3) — (14) Net periodic benefit costs (credits) (c) $ 9 $ 16 $ (3) $ (18) Six Months Ended June 30, Pension Benefits Other Benefits (In millions) 2021 2020 2021 2020 Service cost $ 8 $ 10 $ — $ — Interest cost 4 5 1 1 Expected return on plan assets (4) (5) — — Amortization: – prior service credit (3) (4) (8) (9) – actuarial loss 3 5 1 1 Net settlement loss (a) 5 16 — — Net curtailment gain (b) — (3) — (14) Net periodic benefit costs (credits) (c) $ 13 $ 24 $ (6) $ (21) (a) Settlements are recognized as they occur, once it is probable that lump sum payments from a plan for a given year will exceed the plan’s total service and interest cost for that year. (b) Related to workforce reductions, which reduced the future expected years of service for employees participating in the plans. (c) Net periodic benefit costs (credits) reflects a calculated market-related value of plan assets which recognizes changes in fair value over three years.

Reclassifications Out of Accu_2

Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Schedule of Amounts Reclassified out of Accumulated Other Comprehensive Income (Loss)	The following table presents a summary of amounts reclassified from accumulated other comprehensive income (loss): Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Income Statement Line Postretirement and postemployment plans Amortization of prior service credit $ 5 $ 7 $ 11 $ 13 Other net periodic benefit costs Amortization of actuarial loss (1) (3) (4) (6) Other net periodic benefit costs Net settlement loss (5) (14) (5) (16) Other net periodic benefit costs Net curtailment gain — 17 — 17 Other net periodic benefit costs Interest rate swaps Reclassification of de-designated forward interest rate swaps (30) — (28) — Net interest and other Total reclassifications of (income) expense, net of tax (a) $ (31) $ 7 $ (26) $ 8 Net income (loss)

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	6 Months Ended
	Jun. 30, 2021
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Six Months Ended June 30, (In millions) 2021 2020 Included in operating activities: Interest paid, net of amounts capitalized $ 123 $ 126 Income taxes paid to (received from) taxing authorities, net of refunds (a) $ 9 $ 4 Noncash investing activities: Increase (decrease) in asset retirement costs $ 38 $ (6) (a) The six months ended June 30, 2020 includes $4 million related to tax refunds.

Equity Method Investments (Tabl

Equity Method Investments (Tables)	6 Months Ended
	Jun. 30, 2021
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Equity Method Investments	During the periods ended June 30, 2021 and December 31, 2020 our equity method investees were considered related parties and are summarized in the following table: (In millions) Ownership as of June 30, 2021 June 30, 2021 December 31, 2020 EGHoldings (a) 60% $ 138 $ 113 Alba Plant LLC (b) 52% 168 168 AMPCO (c) 45% 152 166 Total $ 458 $ 447 (a) EGHoldings is engaged in LNG production activity. (b) Alba Plant LLC processes LPG. (c) AMPCO is engaged in methanol production activity. Summarized financial information for equity method investees is as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Income data: Revenues and other income $ 246 $ 111 $ 481 $ 283 Income (loss) from operations 111 (10) 207 (40) Net income (loss) $ 85 $ (13) $ 157 $ (39)

Income (loss) and Dividends p_3

Income (loss) and Dividends per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)	4		7		5	7
Net income (loss)	$ 16	$ 97	$ (750)	$ (46)	$ 113	$ (796)
Weighted average common shares outstanding (in shares)	789		790		790	793
Effect of dilutive securities (in shares)	0		0		1	0
Weighted average common shares, diluted (in shares)	789		790		791	793
Net income (loss) per share:
Basic (in dollars per share)	$ 0.02		$ (0.95)		$ 0.14	$ (1)
Diluted (in dollars per share)	0.02		(0.95)		0.14	(1)
Dividends per share (in dollars per share)	$ 0.04	$ 0.03	$ 0	$ 0.05	$ 0.07	$ 0.05

Revenues - Narrative (Details)

Revenues - Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Receivables from contract with customer	$ 841	$ 572

Revenues - Revenues from Contra

Revenues - Revenues from Contracts with Customers by Product Type and Geographic Areas (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 1,254	$ 490	$ 2,431	$ 1,514
United States E&P
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,189	462	2,321	1,432
United States E&P | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	417	179	751	527
United States E&P | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	476	155	914	503
United States E&P | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	149	69	356	203
United States E&P | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	93	41	204	121
United States E&P | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	54	18	96	78
United States E&P | Crude oil and condensate
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	936	361	1,727	1,189
United States E&P | Crude oil and condensate | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	353	142	612	449
United States E&P | Crude oil and condensate | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	411	147	783	477
United States E&P | Crude oil and condensate | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	71	32	132	116
United States E&P | Crude oil and condensate | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	77	33	154	107
United States E&P | Crude oil and condensate | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	24	7	46	40
United States E&P | Natural gas liquids
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	131	37	247	88
United States E&P | Natural gas liquids | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	33	16	59	31
United States E&P | Natural gas liquids | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	48	3	89	13
United States E&P | Natural gas liquids | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	37	13	74	34
United States E&P | Natural gas liquids | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	11	4	20	7
United States E&P | Natural gas liquids | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2	1	5	3
United States E&P | Natural gas
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	91	54	306	121
United States E&P | Natural gas | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	29	20	76	44
United States E&P | Natural gas | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	17	5	42	13
United States E&P | Natural gas | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	41	24	150	53
United States E&P | Natural gas | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	5	4	30	7
United States E&P | Natural gas | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(1)	1	8	4
United States E&P | Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	31	10	41	34
United States E&P | Other | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2	1	4	3
United States E&P | Other | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
United States E&P | Other | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
United States E&P | Other | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
United States E&P | Other | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	29	9	37	31
International E&P | Equatorial Guinea
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	65	28	110	82
International E&P | Crude oil and condensate | Equatorial Guinea
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	58	20	95	65
International E&P | Natural gas liquids | Equatorial Guinea
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1	1	2	2
International E&P | Natural gas | Equatorial Guinea
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	5	7	12	15
International E&P | Other | Equatorial Guinea
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 1	$ 0	$ 1	$ 0

Segment Information (Details)

Segment Information (Details) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2021USD ($)	Mar. 31, 2021USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Jun. 30, 2021USD ($)segment	Jun. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment					2
Revenues from contracts with customers	$ 1,254		$ 490		$ 2,431	$ 1,514
Net gain (loss) on commodity derivatives	(166)		(70)		(319)	132
Income (loss) from equity method investments	49		(152)		93	(164)
Net gain (loss) on disposal of assets	1		(2)		1	7
Other income	5		6		8	13
Less costs and expenses:
Production	126		129		247	289
Shipping, handling and other operating	167		105		319	249
Exploration	25		26		46	54
Depreciation, depletion and amortization	532		597		1,028	1,241
Impairments	46		0		47	97
Taxes other than income	74		30		148	96
General and administrative	68		88		157	164
Net interest and other	59		69		72	133
Other net periodic benefit costs	1		(7)		(2)	(7)
Loss on early extinguishment of debt	19		0		19	0
Income tax provision (benefit)	10		(15)		20	(18)
Net income (loss)	16	$ 97	(750)	$ (46)	113	(796)
Total assets	17,800		18,567		17,800	18,567	$ 17,956
Capital expenditures	289		139		473	707
Long-lived assets held for use impairment	24		0		25	2
Asset retirement costs of long-lived assets, impairment	22		0		22	0
Goodwill impairment loss				$ 95	0	95
Gulf of Mexico
Less costs and expenses:
Asset retirement costs of long-lived assets, impairment	22
Pension Plan
Less costs and expenses:
Other net periodic benefit costs	5		14		5	16
Pension curtailment gain	0		3		0	3
Not Allocated to Segments
Segment Reporting Information [Line Items]
Revenues from contracts with customers	0		0		0	0
Net gain (loss) on commodity derivatives	(75)		(96)		(157)	75
Income (loss) from equity method investments	0		(152)		0	(152)
Net gain (loss) on disposal of assets	1		(2)		1	7
Other income	0		1		1	2
Less costs and expenses:
Production	0		0		0	0
Shipping, handling and other operating	12		13		16	14
Exploration	7		0		7	0
Depreciation, depletion and amortization	8		6		13	12
Impairments	46				47	97
Taxes other than income	(2)		0		(2)	0
General and administrative	37		53		101	93
Net interest and other	59		69		72	133
Other net periodic benefit costs	1		(7)		(2)	(7)
Loss on early extinguishment of debt	19				19
Income tax provision (benefit)	(2)		(4)		(2)	(6)
Net income (loss)	(259)		(379)		(424)	(404)
Total assets	1,006		632		1,006	632
Capital expenditures	3		2		4	9
Severance costs			13		12	13
Loss on lease termination					13
Not Allocated to Segments | Eagle Ford
Less costs and expenses:
Long-lived assets held for use impairment	24				24
Not Allocated to Segments | Gulf of Mexico
Less costs and expenses:
Asset retirement costs of long-lived assets, impairment	22				22
Not Allocated to Segments | Interest Rate Contract, Maturing November 1, 2022 | Not Designated as Hedges
Less costs and expenses:
Loss on interest rate swap	22
Gain on interest rate swap					19
Not Allocated to Segments | Interest Rate Contract, Maturing June 1, 2025 | Not Designated as Hedges
Less costs and expenses:
Gain on interest rate swap	31				31
Not Allocated to Segments | Pension Plan
Less costs and expenses:
Pension settlement loss			14			16
Pension curtailment gain			17			17
United States E&P
Segment Reporting Information [Line Items]
Revenues from contracts with customers	1,189		462		2,321	1,432
United States E&P | Eagle Ford
Segment Reporting Information [Line Items]
Revenues from contracts with customers	417		179		751	527
United States E&P | Operating Segments
Segment Reporting Information [Line Items]
Revenues from contracts with customers	1,189		462		2,321	1,432
Net gain (loss) on commodity derivatives	(91)		26		(162)	57
Income (loss) from equity method investments	0		0		0	0
Net gain (loss) on disposal of assets	0		0		0	0
Other income	3		3		4	7
Less costs and expenses:
Production	113		114		224	257
Shipping, handling and other operating	153		91		297	231
Exploration	18		26		39	54
Depreciation, depletion and amortization	506		569		978	1,186
Impairments	0				0	0
Taxes other than income	76		30		150	96
General and administrative	27		32		50	64
Net interest and other	0		0		0	0
Other net periodic benefit costs	0		0		0	0
Loss on early extinguishment of debt	0				0
Income tax provision (benefit)	1		(6)		6	(7)
Net income (loss)	207		(365)		419	(385)
Total assets	15,747		16,791		15,747	16,791
Capital expenditures	284		137		467	698
Int'l E&P | Operating Segments
Segment Reporting Information [Line Items]
Revenues from contracts with customers	65		28		110	82
Net gain (loss) on commodity derivatives	0		0		0	0
Income (loss) from equity method investments	49		0		93	(12)
Net gain (loss) on disposal of assets	0		0		0	0
Other income	2		2		3	4
Less costs and expenses:
Production	13		15		23	32
Shipping, handling and other operating	2		1		6	4
Exploration	0		0		0	0
Depreciation, depletion and amortization	18		22		37	43
Impairments	0				0	0
Taxes other than income	0		0		0	0
General and administrative	4		3		6	7
Net interest and other	0		0		0	0
Other net periodic benefit costs	0		0		0	0
Loss on early extinguishment of debt	0				0
Income tax provision (benefit)	11		(5)		16	(5)
Net income (loss)	68		(6)		118	(7)
Total assets	1,047		1,144		1,047	1,144
Capital expenditures	$ 2		$ 0		$ 2	$ 0

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Effective income tax rate	38.00%	2.00%	15.00%	2.00%

Credit Losses (Details)

Credit Losses (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance as of January 1	$ 22	$ 11
Current period provision	(2)	22
Current period write offs	(1)	(13)
Recoveries of amounts previously reserved	0	(10)
Ending balance	19	22
Cumulative Effect, Period of Adoption, Adjustment
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance as of January 1	$ 0	12
Ending balance		0
Joint Interest Receivables
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision		10
Trade Receivables
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision		$ 12

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Crude oil and natural gas	$ 12	$ 10
Supplies and other items	66	66
Inventories	$ 78	$ 76

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 15,019	$ 15,638
Exploratory well costs capitalized greater than one year after completion of drilling	158	98
Operating Segments | United States E&P
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	14,583	15,156
Operating Segments | International E&P
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	380	414
Corporate
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 56	$ 68

Impairments (Details)

Impairments (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Impaired Long-Lived Assets Held and Used [Line Items]
Long-lived assets held for use impairment	$ 24	$ 0		$ 25	$ 2
Asset retirement costs of long-lived assets, impairment	22	0		22	0
Goodwill impairment loss			$ 95	0	95
Equity method investment impairment	0	152		0	152
Asset retirement obligation	296	252		296	252	$ 254	$ 255
Gulf of Mexico
Impaired Long-Lived Assets Held and Used [Line Items]
Asset retirement costs of long-lived assets, impairment	22
Asset retirement obligation	29			29		$ 7
Fair Value
Impaired Long-Lived Assets Held and Used [Line Items]
Long-lived assets held for use	0	0		0	0
Asset retirement costs of long-lived assets	0	0		0	0
Goodwill	0	0		0	0
Equity method investment	$ 0	$ 142		$ 0	$ 142

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance as of January 1			$ 254	$ 255
Incurred liabilities, including acquisitions			6	2
Settled liabilities, including dispositions			(2)	(3)
Accretion expense (included in depreciation, depletion and amortization)			6	6
Revisions of estimates			32	(8)
Ending balance as of June 30, total	$ 296	$ 252	296	252
Asset retirement obligation, current	24	10	24	10
Impairments	22	$ 0	22	$ 0
Gulf of Mexico
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance as of January 1			7
Revisions of estimates	29
Ending balance as of June 30, total	29		29
Asset retirement obligation, current	14		$ 14
Impairments	$ 22

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Leases [Abstract]
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other noncurrent assets	Other noncurrent assets
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	mro:Deferredcreditandotherliabilities	mro:Deferredcreditandotherliabilities
Right-of-use asset	$ 92	$ 133
Current portion of long-term lease liability	52	70
Long-term lease liability	$ 44	$ 67

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions	6 Months Ended
	Jun. 30, 2021USD ($)
Leases [Abstract]
Annual payments to be received	$ 6
Maximum financing available	340
Total costs incurred under lease	$ 214
Term of contract	5 years
Finance lease extension term	5 years
Residual value guarantee	89.00%

Leases - Lease Payments to be R

Leases - Lease Payments to be Received (Details) $ in Millions	Jun. 30, 2021USD ($)
Leases [Abstract]
2021	$ 4
2022	6
2023	6
2024	6
2025	6
Thereafter	54
Total undiscounted cash flows	$ 82

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill impairment loss	$ 95	$ 0	$ 95

Derivatives - Balance Sheet Com

Derivatives - Balance Sheet Components (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Asset	$ 63	$ 39
Liability	190	49
Net Asset (Liability)	(127)	(10)
Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	63	20
Liability	182	33
Net Asset (Liability)	(119)	(13)
Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Asset	0	19
Liability	8	16
Net Asset (Liability)	(8)	3
Commodity | Other current assets | Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset		3
Liability		1
Net Asset (Liability)		2
Commodity | Other current liabilities | Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	0	7
Liability	181	32
Net Asset (Liability)	(181)	(25)
Interest Rate | Other current liabilities | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Asset	0
Liability	2
Net Asset (Liability)	(2)
Interest Rate | Other noncurrent assets | Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	63	10
Liability	0	0
Net Asset (Liability)	63	10
Interest Rate | Other noncurrent assets | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Asset		19
Liability		0
Net Asset (Liability)		19
Interest Rate | Deferred credits and other liabilities | Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	0
Liability	1
Net Asset (Liability)	(1)
Interest Rate | Deferred credits and other liabilities | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Asset	0	0
Liability	6	16
Net Asset (Liability)	$ (6)	$ (16)

Derivatives - Outstanding Deriv

Derivatives - Outstanding Derivative Contracts (Details) - Not Designated as Hedges	Jun. 30, 2021Bbls_per_dayMMBTU_per_day$ / bbl$ / MMBTU
Three-Way Collars - Crude Oil 2021 Q3
Derivative [Line Items]
Derivative, volume | Bbls_per_day	40,000
Derivative, ceiling	74.07
Derivative, floor	48.75
Derivative, sold put	38.75
Three-Way Collars - Crude Oil 2021 Q4
Derivative [Line Items]
Derivative, volume | Bbls_per_day	40,000
Derivative, ceiling	78.05
Derivative, floor	50
Derivative, sold put	40
Three-Way Collars - Crude Oil 2022, First Half
Derivative [Line Items]
Derivative, volume | Bbls_per_day	10,000
Derivative, ceiling	87.84
Derivative, floor	50
Derivative, sold put	40
Three-Way Collars - Crude Oil 2022, Second Half
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Derivative, ceiling	0
Derivative, floor	0
Derivative, sold put	0
Two-Way Collars - Crude Oil 2021 Q3
Derivative [Line Items]
Derivative, volume | Bbls_per_day	40,000
Derivative, ceiling	59.41
Derivative, floor	39.25
Two-Way Collars - Crude Oil 2021 Q4
Derivative [Line Items]
Derivative, volume | Bbls_per_day	40,000
Derivative, ceiling	58.92
Derivative, floor	39.25
Two-Way Collars - Crude Oil 2022, First Half
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Derivative, ceiling	0
Derivative, floor	0
Two-Way Collars - Crude Oil 2022, Second Half
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Derivative, ceiling	0
Derivative, floor	0
NYMEX Roll Basis Swaps - Crude Oil 2021 Q3
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
NYMEX Roll Basis Swaps - Crude Oil 2021 Q3 | Short
Derivative [Line Items]
Derivative, weighted average price	0
NYMEX Roll Basis Swaps - Crude Oil 2021 Q4
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
NYMEX Roll Basis Swaps - Crude Oil 2021 Q4 | Short
Derivative [Line Items]
Derivative, weighted average price	0
NYMEX Roll Basis Swaps - Crude Oil 2022, First Half
Derivative [Line Items]
Derivative, volume | Bbls_per_day	45,000
NYMEX Roll Basis Swaps - Crude Oil 2022, First Half | Short
Derivative [Line Items]
Derivative, weighted average price	0.56
NYMEX Roll Basis Swaps - Crude Oil 2022, Second Half
Derivative [Line Items]
Derivative, volume | Bbls_per_day	45,000
NYMEX Roll Basis Swaps - Crude Oil 2022, Second Half | Short
Derivative [Line Items]
Derivative, weighted average price	0.56
Two-Way Collars - Natural Gas 2021 Q3
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	200,000
Derivative, ceiling | $ / MMBTU	3.05
Derivative, floor | $ / MMBTU	2.50
Two-Way Collars - Natural Gas 2021 Q4
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	200,000
Derivative, ceiling | $ / MMBTU	3.05
Derivative, floor | $ / MMBTU	2.50
Two-Way Collars - Natural Gas 2022, First
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Derivative, ceiling | $ / MMBTU	0
Derivative, floor | $ / MMBTU	0
Two-Way Collars - Natural Gas 2022, Second Half
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Derivative, ceiling | $ / MMBTU	0
Derivative, floor | $ / MMBTU	0
Henry Hub Basis Swaps - Natural Gas 2021 Q3
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	50,000
Henry Hub Basis Swaps - Natural Gas 2021 Q3 | Short
Derivative [Line Items]
Derivative, weighted average price | $ / MMBTU	2.88
Henry Hub Basis Swaps - Natural Gas 2021 Q4
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	50,000
Henry Hub Basis Swaps - Natural Gas 2021 Q4 | Short
Derivative [Line Items]
Derivative, weighted average price | $ / MMBTU	2.88
Henry Hub Basis Swaps - Natural Gas 2022, First Half
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Henry Hub Basis Swaps - Natural Gas 2022, First Half | Short
Derivative [Line Items]
Derivative, weighted average price | $ / MMBTU	0
Henry Hub Basis Swaps - Natural Gas 2022, Second Half
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Henry Hub Basis Swaps - Natural Gas 2022, Second Half | Short
Derivative [Line Items]
Derivative, weighted average price | $ / MMBTU	0
Fixed Price Ethane Swaps - NGL 2021 Q3
Derivative [Line Items]
Derivative, volume | Bbls_per_day	5,000
Fixed Price Ethane Swaps - NGL 2021 Q3 | Short
Derivative [Line Items]
Derivative, weighted average price	10.92
Fixed Price Ethane Swaps - NGL 2021 Q4
Derivative [Line Items]
Derivative, volume | Bbls_per_day	5,000
Fixed Price Ethane Swaps - NGL 2021 Q4 | Short
Derivative [Line Items]
Derivative, weighted average price	10.92
Fixed Price Ethane Swaps - NGL 2022 First Half
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Price Ethane Swaps - NGL 2022 First Half | Short
Derivative [Line Items]
Derivative, weighted average price	0
Fixed Price Ethane Swaps - NGL 2022 Second Half
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Price Ethane Swaps - NGL 2022 Second Half | Short
Derivative [Line Items]
Derivative, weighted average price	0
Fixed Price Propane Swaps - NGL 2021 Q3
Derivative [Line Items]
Derivative, volume | Bbls_per_day	5,000
Fixed Price Propane Swaps - NGL 2021 Q3 | Short
Derivative [Line Items]
Derivative, weighted average price	23.19
Fixed Price Propane Swaps - NGL 2021 Q4
Derivative [Line Items]
Derivative, volume | Bbls_per_day	5,000
Fixed Price Propane Swaps - NGL 2021 Q4 | Short
Derivative [Line Items]
Derivative, weighted average price	23.19
Fixed Price Propane Swaps - NGL 2022, First Half
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Price Propane Swaps - NGL 2022, First Half | Short
Derivative [Line Items]
Derivative, weighted average price	0
Fixed Price Propane Swaps - NGL 2022, Second Half
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Price Propane Swaps - NGL 2022, Second Half | Short
Derivative [Line Items]
Derivative, weighted average price	0

Derivatives - Schedule of mark-

Derivatives - Schedule of mark-to-market impact and commodity derivative settlements (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Net settlements of derivative instruments	$ 84	$ 78	$ 95	$ 91
Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivative instruments, net	(75)	(96)	(157)	75
Realized gain (loss) on derivative instruments, net	$ (91)	$ 26	$ (162)	$ 57

Derivatives - Narrative (Detail

Derivatives - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Outstanding debt	$ 4,900		$ 4,900
Senior Unsecured Notes, 3.850%, Due 2025
Derivative Instruments, Gain (Loss) [Line Items]
Outstanding debt	$ 900		$ 900
Interest rate	3.85%		3.85%
Interest Rate Contract, Maturing June 1, 2025
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification from AOCI	$ 31
Interest Rate Contract, Maturing September 9, 2026
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification from AOCI	(1)
Not Designated as Hedges | Interest Rate
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification of de-designated forward interest rate swaps		$ 2
Not Designated as Hedges | Interest Rate Contract, Maturing November 1, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Loss on interest rate swap	22
Gain on interest rate swap			$ 19
Derivative, notional amount	500		500	$ 500
Not Designated as Hedges | Interest Rate Contract, Maturing June 1, 2025
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	350		350
Not Designated as Hedges | Interest Rate Contract, Maturing September 9, 2026
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	25		25
Not Designated as Hedges | Interest Rate Contract, Maturing September 9, 2026 | De-designated as cash flow hedge
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	25		25
Designated as Hedging Instrument | Interest Rate Contract, Maturing June 1, 2025
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount				350
Designated as Hedging Instrument | Interest Rate Contract, Maturing June 1, 2025 | Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount				350
Designated as Hedging Instrument | Interest Rate Contract, Maturing September 9, 2026
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 295		$ 295	$ 320
Designated as Hedging Instrument | Interest Rate Contract, Maturing September 9, 2026 | Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount					$ 320

Derivatives - Schedule of Termi

Derivatives - Schedule of Terminated Interest Rate Swap Agreements (Details) - Not Designated as Hedges - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Interest Rate Contract, Maturing November 1, 2022
Derivative [Line Items]
Derivative, notional amount	$ 500	$ 500
Weighted average interest rate, LIBOR	0.99%	0.99%
Interest Rate Contract, Maturing June 1, 2025
Derivative [Line Items]
Derivative, notional amount	$ 350
Weighted average interest rate, LIBOR	0.95%
Interest Rate Contract, Maturing September 9, 2026
Derivative [Line Items]
Derivative, notional amount	$ 25
Weighted average interest rate, LIBOR	1.45%

Derivatives - Schedule of Inter

Derivatives - Schedule of Interest Rate Swap Agreements (Details) - Designated as Hedging Instrument - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Interest Rate Contract, Maturing June 1, 2025
Derivative [Line Items]
Derivative, notional amount		$ 350
Weighted average interest rate, LIBOR		0.95%
Interest Rate Contract, Maturing September 9, 2026
Derivative [Line Items]
Derivative, notional amount	$ 295	$ 320
Weighted average interest rate, LIBOR	1.52%	1.51%

Fair Value Measurements - Fair

Fair Value Measurements - Fair Values - Recurring (Details) - Recurring - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	$ 62	$ 29
Derivative instruments, liabilities	(189)	(39)
Total	(127)	(10)
Interest Rate | Not Designated as Hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	62	10
Interest Rate | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets		19
Derivative instruments, liabilities	(8)	(16)
Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, liabilities	(181)	(23)
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	0	0
Derivative instruments, liabilities	(30)	0
Total	(30)	0
Level 1 | Interest Rate | Not Designated as Hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	0	0
Level 1 | Interest Rate | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets		0
Derivative instruments, liabilities	0	0
Level 1 | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, liabilities	(30)	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	62	29
Derivative instruments, liabilities	(159)	(39)
Total	(97)	(10)
Level 2 | Interest Rate | Not Designated as Hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	62	10
Level 2 | Interest Rate | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets		19
Derivative instruments, liabilities	(8)	(16)
Level 2 | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, liabilities	(151)	(23)
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	0	0
Derivative instruments, liabilities	0	0
Total	0	0
Level 3 | Interest Rate | Not Designated as Hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	0	0
Level 3 | Interest Rate | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets		0
Derivative instruments, liabilities	0	0
Level 3 | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, liabilities	$ 0	$ 0

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair Values - Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Fair Value
Financial assets
Current assets	$ 13	$ 4
Other noncurrent assets	12	24
Total financial assets	25	28
Financial liabilities
Current liabilities	93	72
Long-term debt, including current portion	5,735	6,077
Deferred credits and other liabilities	69	103
Total financial liabilities	5,897	6,252
Carrying Amount
Financial assets
Current assets	12	4
Other noncurrent assets	27	37
Total financial assets	39	41
Financial liabilities
Current liabilities	124	103
Long-term debt, including current portion	4,931	5,431
Deferred credits and other liabilities	50	76
Total financial liabilities	$ 5,105	$ 5,610

Debt - Revolving Credit Facilit

Debt - Revolving Credit Facility (Details) - Revolving Credit Facility	May 28, 2023USD ($)	Jun. 30, 2021USD ($)	Jun. 21, 2021USD ($)	Jun. 20, 2021USD ($)
Line of Credit Facility [Line Items]
Maximum borrowing capacity			$ 3,100,000,000	$ 3,000,000,000
Line of credit, outstanding amount		$ 0
Covenant, ratio of indebtedness to net capital, maximum		0.65
Ratio of indebtedness to net capital		0.24
Forecast
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 3,000,000,000

Debt - Debt Redemption (Details

Debt - Debt Redemption (Details) - Senior Unsecured Note Due 2022 $ in Millions	Mar. 30, 2021USD ($)
Debt Instrument [Line Items]
Long-term debt	$ 500
Interest rate	2.80%
Costs related to make-whole provision premium and write off of unamortized discount and issuance costs	$ 19

Debt - Long-Term Debt (Details)

Debt - Long-Term Debt (Details) $ in Millions	Jun. 30, 2021USD ($)
Debt Instrument [Line Items]
Outstanding debt	$ 4,900
Senior Unsecured Notes, 3.850%, Due 2025
Debt Instrument [Line Items]
Outstanding debt	$ 900
Interest rate	3.85%
Senior Unsecured Notes, 3.850%, Due 2025 | Minimum
Debt Instrument [Line Items]
Estimated make-whole provision premium	$ 85
Senior Unsecured Notes, 3.850%, Due 2025 | Maximum
Debt Instrument [Line Items]
Estimated make-whole provision premium	105
Senior Unsecured Notes, 4.400%, Due 2027 | Unsecured Debt
Debt Instrument [Line Items]
Debt instrument outstanding amount	$ 1,000

Stockholders' Equity (Details)

Stockholders' Equity (Details) $ in Millions	6 Months Ended
	Jun. 30, 2021USD ($)shares
Equity [Abstract]
Shares repurchased (in shares) | shares	0
Value of stock repurchased for restricted stock award tax obligation	$ 9
Stock repurchase program, remaining authorized repurchase amount	$ 1,300

Incentive Based Compensation -

Incentive Based Compensation - Stock Options, Restricted Stock Awards and Restricted Stock Units (Details)	6 Months Ended
	Jun. 30, 2021$ / sharesshares
Number of Shares
Outstanding, beginning (in shares) | shares	6,014,255
Granted (in shares) | shares	0
Exercised/Vested (in shares) | shares	(384,889)
Canceled (in shares) | shares	(1,106,590)
Outstanding, ending (in shares) | shares	4,522,776
Weighted Average Exercise Price
Outstanding, beginning (in dollars per share) | $ / shares	$ 21
Granted (in dollars per share) | $ / shares	0
Exercised/Vested (in dollars per share) | $ / shares	7.34
Canceled (in dollars per share) | $ / shares	22.82
Outstanding, ending (in dollars per share) | $ / shares	$ 21.72
Restricted Stock Awards & Units
Awards
Outstanding, beginning (in shares) | shares	7,851,754
Granted (in shares) | shares	2,297,929
Exercised/Vested (in shares) | shares	(2,896,748)
Canceled (in shares) | shares	(893,808)
Outstanding, ending (in shares) | shares	6,359,127
Weighted Average Grant Date Fair Value
Outstanding, beginning (in dollars per share) | $ / shares	$ 11.72
Granted (in dollars per share) | $ / shares	11.20
Exercised/Vested (in dollars per share) | $ / shares	12.56
Canceled (in dollars per share) | $ / shares	11.97
Outstanding, ending (in dollars per share) | $ / shares	$ 11.12

Incentive Based Compensation _2

Incentive Based Compensation - Stock-based Performance Unit Awards (Details)	6 Months Ended
	Jun. 30, 2021$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares, payout determination, share price trading day duration	30 days
Performance period	2 years
Vesting Percentage, Lock Level One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage, banking feature lock threshold percentage	50.00%
Vesting Percentage, Lock Level Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage, banking feature lock threshold percentage	100.00%
Performance Unit - Share Settlement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares) | shares	307,473
Grant date fair value (in dollars per share) | $ / shares	$ 18.07
Performance Unit - Share Settlement | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	0.00%
Performance Unit - Share Settlement | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	200.00%
Performance Shares | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	0.00%
Performance Shares | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	200.00%
Performance Unit - Cash Settlement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares) | shares	307,473
Grant date fair value (in dollars per share) | $ / shares	$ 27.32

Defined Benefit Postretiremen_3

Defined Benefit Postretirement Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Amortization:
Net settlement loss	$ 1	$ (7)	$ (2)	$ (7)
Estimated future contributions over the remainder of the current year	9		9
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	5	8	10
Interest cost	2	2	4	5
Expected return on plan assets	(2)	(2)	(4)	(5)
Amortization:
– prior service credit	(1)	(2)	(3)	(4)
– actuarial loss	1	2	3	5
Net settlement loss	5	14	5	16
Net curtailment gain	0	(3)	0	(3)
Net periodic benefit costs (credits)	9	16	13	24
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	1	0	1	1
Expected return on plan assets	0	0	0	0
Amortization:
– prior service credit	(4)	(5)	(8)	(9)
– actuarial loss	0	1	1	1
Net settlement loss	0	0	0	0
Net curtailment gain	0	(14)	0	(14)
Net periodic benefit costs (credits)	$ (3)	$ (18)	(6)	$ (21)
Payment for other postretirement benefits			5
Funded Plan
Amortization:
Payment for pension benefits			14
Unfunded Plan
Amortization:
Payment for pension benefits			$ 2

Reclassifications Out of Accu_3

Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit (costs) credits	$ (1)		$ 7		$ 2	$ 7
Net interest and other	(59)		(69)		(72)	(133)
Net income (loss)	16	$ 97	(750)	$ (46)	113	(796)
Reclassification out of Accumulated Other Comprehensive Income (Loss) | Amortization of prior service credit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit (costs) credits	5		7		11	13
Reclassification out of Accumulated Other Comprehensive Income (Loss) | Amortization of actuarial loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit (costs) credits	(1)		(3)		(4)	(6)
Reclassification out of Accumulated Other Comprehensive Income (Loss) | Net settlement loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit (costs) credits	(5)		(14)		(5)	(16)
Reclassification out of Accumulated Other Comprehensive Income (Loss) | Net curtailment gain
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit (costs) credits	0		17		0	17
Reclassification out of Accumulated Other Comprehensive Income (Loss) | Reclassification of de-designated forward interest rate swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net interest and other	(30)		0		(28)	0
Reclassification out of Accumulated Other Comprehensive Income (Loss) | Total reclassifications of (income) expense, net of tax
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	$ (31)		$ 7		$ (26)	$ 8

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Included in operating activities:
Interest paid, net of amounts capitalized	$ 123	$ 126
Income taxes paid to (received from) taxing authorities, net of refunds	9	4
Noncash investing activities:
Increase (decrease) in asset retirement costs	38	(6)
Proceeds from income tax refunds		4
Capital expenditures incurred but not yet paid	$ 85	$ 48

Equity Method Investments - Sch

Equity Method Investments - Schedule of Equity Method Investments (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 458	$ 447
EG Holdings
Schedule of Equity Method Investments [Line Items]
Ownership percentage	60.00%
Equity method investments	$ 138	113
Alba Plant LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage	52.00%
Equity method investments	$ 168	168
AMPCO
Schedule of Equity Method Investments [Line Items]
Ownership percentage	45.00%
Equity method investments	$ 152	$ 166

Equity Method Investments - Sum

Equity Method Investments - Summarized Financial Information (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Schedule of Equity Method Investments [Line Items]
Revenues and other income	$ 1,143		$ 272		$ 2,214	$ 1,502
Income (loss) from operations	105		(703)		222	(688)
Net income (loss)	16	$ 97	(750)	$ (46)	113	(796)
Consolidated Equity Method Investments
Schedule of Equity Method Investments [Line Items]
Revenues and other income	246		111		481	283
Income (loss) from operations	111		(10)		207	(40)
Net income (loss)	$ 85		$ (13)		$ 157	$ (39)

Equity Method Investments - Nar

Equity Method Investments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Equity Method Investments and Joint Ventures [Abstract]
Revenue from related parties	$ 8	$ 10	$ 16	$ 20
Due from related parties	18		18		$ 24
Due to related parties	$ 6		$ 6		$ 13

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020
Loss Contingencies [Line Items]
Guarantees recorded	$ 4	$ 4
Contingent royalty liability	121	121
Contingent capital and expense receivable, noncurrent	24	24
Revisions of estimates		32	$ (8)
Gulf of Mexico
Loss Contingencies [Line Items]
Revisions of estimates	29
Accounts payable
Loss Contingencies [Line Items]
Contingent royalty liability	111	111
Other current liabilities
Loss Contingencies [Line Items]
Contingent royalty liability	10	10
Performance of Equatorial Guinea LNG Operations, S.A.
Loss Contingencies [Line Items]
Guarantor obligations, maximum exposure	91	91
Performance of Alba Plant LLC.
Loss Contingencies [Line Items]
Guarantor obligations, maximum exposure	$ 25	$ 25