Marathon Oil (MRO) 10-Q 4 Nov 21 2021 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2021	Oct. 29, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 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	990 Town and Country Boulevard,
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77024-2217
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		778,536,897
Document Fiscal Period Focus	Q3
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 - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues and other income:
Revenues from contracts with customers	$ 1,438	$ 761	$ 3,869	$ 2,275
Net gain (loss) on commodity derivatives	(79)	(1)	(398)	131
Income (loss) from equity method investments	86	(10)	179	(174)
Net gain on disposal of assets	7	1	8	8
Other income	1	3	9	16
Total revenues and other income	1,453	754	3,667	2,256
Costs and expenses:
Production	131	129	378	418
Shipping, handling and other operating	219	183	538	432
Exploration	63	27	109	81
Depreciation, depletion and amortization	522	554	1,550	1,795
Impairments	13	1	60	98
Taxes other than income	88	49	236	145
General and administrative	70	53	227	217
Total costs and expenses	1,106	996	3,098	3,186
Income (loss) from operations	347	(242)	569	(930)
Net interest and other	(57)	(62)	(129)	(195)
Other net periodic benefit (costs) credits	0	(6)	2	1
Loss on early extinguishment of debt	(102)	0	(121)	0
Income (loss) before income taxes	188	(310)	321	(1,124)
Provision (benefit) for income taxes	4	7	24	(11)
Net income (loss)	$ 184	$ (317)	$ 297	$ (1,113)
Net income (loss) per share:
Basic (in dollars per share)	$ 0.23	$ (0.40)	$ 0.38	$ (1.41)
Diluted (in dollars per share)	$ 0.23	$ (0.40)	$ 0.38	$ (1.41)
Weighted average common shares outstanding:
Basic (in shares)	789	790	791	792
Diluted (in shares)	789	790	791	792

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 184	$ (317)	$ 297	$ (1,113)
Other comprehensive income (loss), net of tax
Change in actuarial gain (loss) and other for postretirement and postemployment plans	4	9	17	(33)
Change in derivative hedges unrecognized gain (loss)	1	11	20	(15)
Reclassification of de-designated forward interest rate swaps	0	0	(28)	0
Other comprehensive income (loss)	5	20	9	(48)
Comprehensive income (loss)	$ 189	$ (297)	$ 306	$ (1,161)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 485	$ 742
Receivables, less reserve of $19 and $22	1,068	747
Inventories	77	76
Other current assets	25	47
Total current assets	1,655	1,612
Equity method investments	489	447
Property, plant and equipment, less accumulated depreciation, depletion and amortization of $21,914 and $20,358	14,734	15,638
Other noncurrent assets	283	259
Total assets	17,161	17,956
Current liabilities:
Accounts payable	1,028	837
Payroll and benefits payable	64	57
Accrued taxes	131	72
Other current liabilities	417	247
Long-term debt due within one year	36	0
Total current liabilities	1,676	1,213
Long-term debt	3,977	5,404
Deferred tax liabilities	132	163
Defined benefit postretirement plan obligations	137	180
Asset retirement obligations	286	241
Deferred credits and other liabilities	157	194
Total liabilities	6,365	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 September 30, 2021 and December 31, 2020)	937	937
Held in treasury, at cost – 148 million shares	(4,105)	(4,089)
Additional paid-in capital	7,213	7,174
Retained earnings	6,669	6,466
Accumulated other comprehensive income	82	73
Total stockholders’ equity	10,796	10,561
Total liabilities and stockholders’ equity	$ 17,161	$ 17,956

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Receivables reserve	$ 19	$ 22
Property, plant and equipment, accumulated depreciation	$ 21,914	$ 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 - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating activities:
Net income (loss)	$ 297	$ (1,113)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	1,550	1,795
Impairments	60	98
Exploratory dry well costs and unproved property impairments	101	63
Net gain on disposal of assets	(8)	(8)
Loss on early extinguishment of debt	121	0
Deferred income taxes	(32)	(2)
Unrealized (gain) loss on derivative instruments, net	130	(39)
Pension and other post retirement benefits, net	(25)	(35)
Stock-based compensation	29	43
Equity method investments, net	(57)	189
Changes in:
Current receivables	(313)	467
Inventories	(1)	(5)
Current accounts payable and accrued liabilities	228	(478)
Other current assets and liabilities	66	83
All other operating, net	(53)	(3)
Net cash provided by operating activities	2,093	1,055
Investing activities:
Additions to property, plant and equipment	(772)	(1,090)
Additions to other assets	0	15
Acquisitions, net of cash acquired	0	(1)
Disposal of assets, net of cash transferred to the buyer	29	9
Equity method investments - return of capital	15	7
All other investing, net	0	0
Net cash used in investing activities	(728)	(1,060)
Financing activities:
Borrowings	0	400
Debt repayment	(1,400)	0
Debt extinguishment costs	(117)	0
Purchases of common stock	(10)	(92)
Dividends paid	(94)	(40)
All other financing, net	(1)	(2)
Net cash provided by (used in) financing activities	(1,622)	266
Net increase (decrease) in cash and cash equivalents	(257)	261
Cash and cash equivalents at beginning of period	742	858
Cash and cash equivalents at end of period	$ 485	$ 1,119

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - 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)	(1,113)
Other comprehensive income (loss)	(48)
Ending balance at Sep. 30, 2020	10,892		0	937	(4,089)	7,159	6,828		57
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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - stock-based compensation	0				(2)	2
Stock-based compensation	14					14
Net income (loss)	(317)						(317)
Other comprehensive income (loss)	20								20
Ending balance at Sep. 30, 2020	10,892		0	937	(4,089)	7,159	6,828		57
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)	297
Other comprehensive income (loss)	9
Ending balance at Sep. 30, 2021	10,796		0	937	(4,105)	7,213	6,669		82
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
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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - stock-based compensation	1				0	1
Shares repurchased	0				0
Stock-based compensation	11					11
Net income (loss)	184						184
Other comprehensive income (loss)	5								5
Dividends paid	(39)						(39)
Ending balance at Sep. 30, 2021	$ 10,796		$ 0	$ 937	$ (4,105)	$ 7,213	$ 6,669		$ 82

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended					9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Stockholders' Equity [Abstract]
Dividends paid (in dollars per share)	$ 0.05	$ 0.04	$ 0.03	$ 0	$ 0.05	$ 0.12	$ 0.05

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 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 third quarter and first nine months of 2021 are not necessarily indicative of the results to be expected for the full year.

Accounting Standards

Accounting Standards	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Accounting Standards	Accounting StandardsNo accounting standards were adopted in the third quarter or first nine 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	9 Months Ended
	Sep. 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 of stock options for each of the three and nine months ended September 30, 2021 and 6 million of stock options for each of the three and nine months ended September 30, 2020 that were antidilutive. Three Months Ended September 30, Nine Months Ended September 30, (In millions, except per share data) 2021 2020 2021 2020 Net income (loss) $ 184 $ (317) $ 297 $ (1,113) Weighted average common shares outstanding 789 790 791 792 Effect of dilutive securities — — — — Weighted average common shares, diluted 789 790 791 792 Net income (loss) per share: Basic $ 0.23 $ (0.40) $ 0.38 $ (1.41) Diluted $ 0.23 $ (0.40) $ 0.38 $ (1.41) Dividends per share $ 0.05 $ — $ 0.12 $ 0.05

Revenues

Revenues	9 Months Ended
	Sep. 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 September 30, 2021 and December 31, 2020, receivables from contracts with customers, included in receivables, less reserves were $900 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 nine months ended September 30: United States Three Months Ended September 30, 2021 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 391 $ 425 $ 74 $ 75 $ 19 $ 984 Natural gas liquids 50 63 53 12 5 183 Natural gas 38 29 62 12 3 144 Other 2 — — — 62 64 Revenues from contracts with customers $ 481 $ 517 $ 189 $ 99 $ 89 $ 1,375 Three Months Ended September 30, 2020 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 190 $ 230 $ 65 $ 53 $ 14 $ 552 Natural gas liquids 22 15 28 7 1 73 Natural gas 18 9 33 6 3 69 Other 1 — — — 27 28 Revenues from contracts with customers $ 231 $ 254 $ 126 $ 66 $ 45 $ 722 Nine Months Ended September 30, 2021 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 1,003 $ 1,208 $ 206 $ 229 $ 65 $ 2,711 Natural gas liquids 109 152 127 32 10 430 Natural gas 114 71 212 42 11 450 Other 6 — — — 99 105 Revenues from contracts with customers $ 1,232 $ 1,431 $ 545 $ 303 $ 185 $ 3,696 Nine Months Ended September 30, 2020 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 639 $ 707 $ 181 $ 160 $ 54 $ 1,741 Natural gas liquids 53 28 62 14 4 161 Natural gas 62 22 86 13 7 190 Other 4 — — — 58 62 Revenues from contracts with customers $ 758 $ 757 $ 329 $ 187 $ 123 $ 2,154 International (E.G.) Three Months Ended September 30, Nine Months Ended September 30, (In millions) 2021 2020 2021 2020 Crude oil and condensate $ 56 $ 31 $ 151 $ 96 Natural gas liquids — 1 2 3 Natural gas 6 7 18 22 Other 1 — 2 — Revenues from contracts with customers $ 63 $ 39 $ 173 $ 121

Segment Information

Segment Information	9 Months Ended
	Sep. 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 September 30, 2021 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 1,375 $ 63 $ — $ 1,438 Net gain (loss) on commodity derivatives (106) — 27 (b) (79) Income (loss) from equity method investments — 86 — 86 Net gain on disposal of assets — — 7 7 Other income — — 1 1 Less costs and expenses: Production 119 12 — 131 Shipping, handling and other operating 209 7 3 219 Exploration 15 — 48 (c) 63 Depreciation, depletion and amortization 499 17 6 522 Impairments — — 13 (d) 13 Taxes other than income 88 — — 88 General and administrative 29 3 38 70 Net interest and other — — 57 (e) 57 Other net periodic benefit costs — — — — Loss on early extinguishment of debt — — 102 (f) 102 Income tax provision (benefit) 5 17 (18) 4 Segment income (loss) $ 305 $ 93 $ (214) $ 184 Total assets $ 15,528 $ 1,071 $ 562 $ 17,161 Capital expenditures (a) $ 303 $ 2 $ 3 $ 308 (a) Includes accruals. (b) Unrealized gain on commodity derivative instruments (See Note 14 ). (c) Includes unproved property impairments of $20 million for Louisiana exploration leases and $16 million related to the disposition of a Permian lease. Also includes $12 million of dry well costs associated with drilled and uncompleted wells, primarily in Permian (See Note 9 ). (d) Includes impairments of $5 million for proved properties in Permian (See Note 10 ) and $8 million associated with decommissioning costs for non-producing long-lived assets in GOM (See Note 10 , Note 11 , and Note 23 ). (e) Includes a $5 million gain on 2022 interest rate swaps and a $3 million gain on 2025 interest rate swaps (See Note 14 ). (f) Represents costs related to a make-whole provision premium and the write off of issuance costs related to the redemption of the 2025 Notes in September 2021 (See Note 16 ). Three Months Ended September 30, 2020 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 722 $ 39 $ — $ 761 Net gain (loss) on commodity derivatives 35 — (36) (b) (1) Income (loss) from equity method investments — 8 (18) (10) Net gain on disposal of assets — — 1 1 Other income 1 1 1 3 Less costs and expenses: Production 118 11 — 129 Shipping, handling and other operating 154 1 28 183 Exploration 21 — 6 27 Depreciation, depletion and amortization 530 19 5 554 Impairments — — 1 1 Taxes other than income 48 — 1 49 General and administrative 25 3 25 53 Net interest and other — — 62 62 Other net periodic benefit costs — — 6 (c) 6 Income tax provision (benefit) (3) 6 4 7 Segment income (loss) $ (135) $ 8 $ (190) $ (317) Total assets $ 16,396 $ 1,104 $ 1,163 $ 18,663 Capital expenditures (a) $ 176 $ — $ 1 $ 177 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 14 ). (c) Includes pension settlement loss of $9 million (See Note 19 ). Nine Months Ended September 30, 2021 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 3,696 $ 173 $ — $ 3,869 Net loss on commodity derivatives (268) — (130) (b) (398) Income (loss) from equity method investments — 179 — 179 Net gain on disposal of assets — — 8 8 Other income 4 3 2 9 Less costs and expenses: Production 343 35 — 378 Shipping, handling and other operating 506 13 19 538 Exploration 54 — 55 (c) 109 Depreciation, depletion and amortization 1,477 54 19 1,550 Impairments — — 60 (d) 60 Taxes other than income 238 — (2) 236 General and administrative 79 9 139 (e) 227 Net interest and other — — 129 (f) 129 Other net periodic benefit credit — — (2) (2) Loss on early extinguishment of debt — — 121 (g) 121 Income tax provision (benefit) 11 33 (20) 24 Segment income (loss) $ 724 $ 211 $ (638) $ 297 Total assets $ 15,528 $ 1,071 $ 562 $ 17,161 Capital expenditures (a) $ 770 $ 4 $ 7 $ 781 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 14 ). (c) Includes unproved property impairments of $20 million for Louisiana exploration leases and $16 million related to the disposition of a lease in Permian. Also includes $12 million of dry well costs associated with drilled and uncompleted wells, primarily in Permian (See Note 9 ). (d) Includes impairments of $24 million for central facilities in Eagle Ford (See Note 10 ), $5 million for proved properties in Permian (See Note 10 ), and $30 million associated with decommissioning costs for non-producing long-lived assets in GOM (See Note 10 , Note 11 , and Note 23 ). (e) Includes $13 million associated with the termination of an aircraft lease agreement and $12 million arising from severance expenses associated with a workforce reduction. (f) Includes a $24 million gain on 2022 interest rate swaps and a $34 million gain on 2025 interest rate swaps (See Note 14 ). (g) 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 and 2025 Notes in September 2021 (See Note 16 ). Nine Months Ended September 30, 2020 (In millions) U.S. Int’l Not Allocated to Segments Total Revenue from contracts with customers $ 2,154 $ 121 $ — $ 2,275 Net gain on commodity derivatives 92 — 39 (b) 131 Loss from equity method investments — (4) (170) (c) (174) Net gain on disposal of assets — — 8 8 Other income 8 5 3 16 Less costs and expenses: Production 375 43 — 418 Shipping, handling and other operating 385 5 42 432 Exploration 75 — 6 81 Depreciation, depletion and amortization 1,716 62 17 1,795 Impairments — — 98 (d) 98 Taxes other than income 144 — 1 145 General and administrative 89 10 118 (e) 217 Net interest and other — — 195 195 Other net periodic benefit credit — — (1) (f) (1) Income tax provision (benefit) (10) 1 (2) (11) Segment income (loss) $ (520) $ 1 $ (594) $ (1,113) Total assets $ 16,396 $ 1,104 $ 1,163 $ 18,663 Capital expenditures (a) $ 874 $ — $ 10 $ 884 (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 $15 million. (f) Includes pension settlement loss of $25 million and pension curtailment gain of $17 million (See Note 19 ).

Income Taxes

Income Taxes	9 Months Ended
	Sep. 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 nine months ended September 30, 2021 and 2020, our effective income tax rates were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Effective income tax rate 2 % (2) % 7 % 1 % Our effective income tax rate was different from our U.S. statutory tax rate of 21% for the three and nine months ended September 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. At September 30, 2021, we 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. We intend to continue a full valuation allowance on these deferred tax assets until there is sufficient evidence to support the reversal of all or some portion of the allowance. However, if current commodity prices are sustained and absent any additional objective negative evidence, we expect it is reasonably possible that sufficient positive evidence will exist within the next 12 months to adjust our current valuation allowance position. Exact timing and amount of the adjustment to the valuation allowance is unknown as this time.

Credit Losses

Credit Losses	9 Months Ended
	Sep. 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) September 30, 2021 December 31, 2020 Beginning balance as of January 1 $ 22 $ 11 Cumulative-effect adjustment — 12 Current period provision (a) 1 22 Current period write offs (1) (13) Recoveries of amounts previously reserved (3) (10) Ending balance $ 19 $ 22

Inventories

Inventories	9 Months Ended
	Sep. 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) September 30, 2021 December 31, 2020 Crude oil and natural gas $ 13 $ 10 Supplies and other items 64 66 Inventories $ 77 $ 76

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment (In millions) September 30, 2021 December 31, 2020 United States $ 14,317 $ 15,156 International 364 414 Corporate 53 68 Net property, plant and equipment $ 14,734 $ 15,638 As of September 30, 2021 and December 31, 2020, we had $125 million and $98 million , respectively, of e

Impairments

Impairments	9 Months Ended
	Sep. 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 September 30, 2021 2020 (In millions) Fair Value Impairment Fair Value Impairment Long-lived assets held for use $ — $ 5 $ — $ 1 Asset retirement costs of long-lived assets — 8 — — Equity method investment $ — $ — $ 23 $ 18 Nine Months Ended September 30, 2021 2020 (In millions) Fair Value Impairment Fair Value Impairment Long-lived assets held for use $ — $ 30 $ — $ 3 Asset retirement costs of long-lived assets — 30 — — Goodwill — — — 95 Equity method investment $ — $ — $ 119 $ 170 • 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 second quarter, which included the re-routing of existing wells. During the third quarter of 2021, we recorded an impairment expense of $5 million associated with our interests in outside operated conventional assets located in New Mexico. During the nine months ended September 30, 2021, we also recognized an incremental $30 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 $37 million as of September 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 – Impairments for the nine months ended September 30, 2020 include charges recognized for our equity method investments of $170 million. During the second and third quarters of 2020, the continuation of the depressed commodity prices, along with a reduction of our long-term price forecasts of a gas index in which one of our equity method investees transacts, caused us to perform a review of one 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 and we recorded impairments of $152 million in the second quarter of 2020 and an additional $18 million in the third quarter of 2020. The impairments of our equity method investments were recognized in income (loss) from equity method investments in our consolidated statements of income. Additionally, the impairments 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. Impairments for the first nine months of 2020 also included $95 million of goodwill impairment in the International reporting unit. See Note 13

Asset Retirement Obligations

Asset Retirement Obligations	9 Months Ended
	Sep. 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: September 30, (In millions) 2021 2020 Beginning balance as of January 1 $ 254 $ 255 Incurred liabilities, including acquisitions 9 3 Settled liabilities, including dispositions (3) (11) Accretion expense (included in depreciation, depletion and amortization) 9 9 Revisions of estimates 40 (8) Ending balance as of September 30, total $ 309 $ 248 Ending balance as of September 30, short-term $ 23 $ 12 In the first nine months of 2021, we had revisions of estimates totaling $37 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 September 30, 2021, $14 million of these Gulf of Mexico related revisions of estimates were classified as short-term. See Note 23 for further information. Of the $37 million, approximately $30 million was recognized as impairment expense during the nine months ended September 30, 2021. See Note 10 for further information.

Leases

Leases	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Leases	Leases Lessee Balance sheet information related to right-of-use (‘ROU’) assets and lease liabilities was as follows: (In millions) Balance Sheet Location: September 30, 2021 December 31, 2020 ROU assets: Operating leases Other noncurrent assets $ 74 $ 133 Finance leases Other noncurrent assets 35 — Total ROU assets $ 109 $ 133 Lease liabilities: Current liabilities Operating leases Other current liabilities $ 44 $ 70 Finance leases Other current liabilities 5 — Noncurrent liabilities Operating leases Deferred credits and other liabilities 34 67 Finance leases Deferred credits and other liabilities 30 — Total Lease liabilities $ 113 $ 137 Operating 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. Finance Leases In 2018, we signed an agreement with an owner/lessor to construct and lease a new build-to-suit office building in Houston, Texas . As of September 30, 2021, we estimate that project costs total approximately $302 million, including land acquisition and construction costs. The initial lease term is five years and commenced in late September 2021 after the new Houston office was ready for occupancy. In the third quarter of 2021, we recorded a $32 million ROU asset and corresponding lease liability associated with the building, which was classified as a finance lease. At the end of the initial lease term, we can negotiate to extend the lease term for an additional five years, subject to the approval of the participants; purchase the property subject to certain terms and conditions; or remarket the property to an unrelated third party. The lease contains a residual value guarantee of 100% of the total acquisition and construction costs. The weighted-average remaining lease term is five years and the discount rate is 2.25%. Lessor 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 $ 2 2022 6 2023 6 2024 6 2025 6 Thereafter 56 Total undiscounted cash flows $ 82
Leases	Leases Lessee Balance sheet information related to right-of-use (‘ROU’) assets and lease liabilities was as follows: (In millions) Balance Sheet Location: September 30, 2021 December 31, 2020 ROU assets: Operating leases Other noncurrent assets $ 74 $ 133 Finance leases Other noncurrent assets 35 — Total ROU assets $ 109 $ 133 Lease liabilities: Current liabilities Operating leases Other current liabilities $ 44 $ 70 Finance leases Other current liabilities 5 — Noncurrent liabilities Operating leases Deferred credits and other liabilities 34 67 Finance leases Deferred credits and other liabilities 30 — Total Lease liabilities $ 113 $ 137 Operating 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. Finance Leases In 2018, we signed an agreement with an owner/lessor to construct and lease a new build-to-suit office building in Houston, Texas . As of September 30, 2021, we estimate that project costs total approximately $302 million, including land acquisition and construction costs. The initial lease term is five years and commenced in late September 2021 after the new Houston office was ready for occupancy. In the third quarter of 2021, we recorded a $32 million ROU asset and corresponding lease liability associated with the building, which was classified as a finance lease. At the end of the initial lease term, we can negotiate to extend the lease term for an additional five years, subject to the approval of the participants; purchase the property subject to certain terms and conditions; or remarket the property to an unrelated third party. The lease contains a residual value guarantee of 100% of the total acquisition and construction costs. The weighted-average remaining lease term is five years and the discount rate is 2.25%. Lessor 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 $ 2 2022 6 2023 6 2024 6 2025 6 Thereafter 56 Total undiscounted cash flows $ 82
Leases	Leases Lessee Balance sheet information related to right-of-use (‘ROU’) assets and lease liabilities was as follows: (In millions) Balance Sheet Location: September 30, 2021 December 31, 2020 ROU assets: Operating leases Other noncurrent assets $ 74 $ 133 Finance leases Other noncurrent assets 35 — Total ROU assets $ 109 $ 133 Lease liabilities: Current liabilities Operating leases Other current liabilities $ 44 $ 70 Finance leases Other current liabilities 5 — Noncurrent liabilities Operating leases Deferred credits and other liabilities 34 67 Finance leases Deferred credits and other liabilities 30 — Total Lease liabilities $ 113 $ 137 Operating 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. Finance Leases In 2018, we signed an agreement with an owner/lessor to construct and lease a new build-to-suit office building in Houston, Texas . As of September 30, 2021, we estimate that project costs total approximately $302 million, including land acquisition and construction costs. The initial lease term is five years and commenced in late September 2021 after the new Houston office was ready for occupancy. In the third quarter of 2021, we recorded a $32 million ROU asset and corresponding lease liability associated with the building, which was classified as a finance lease. At the end of the initial lease term, we can negotiate to extend the lease term for an additional five years, subject to the approval of the participants; purchase the property subject to certain terms and conditions; or remarket the property to an unrelated third party. The lease contains a residual value guarantee of 100% of the total acquisition and construction costs. The weighted-average remaining lease term is five years and the discount rate is 2.25%. Lessor 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 $ 2 2022 6 2023 6 2024 6 2025 6 Thereafter 56 Total undiscounted cash flows $ 82

Goodwill

Goodwill	9 Months Ended
	Sep. 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	9 Months Ended
	Sep. 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. September 30, 2021 (In millions) Asset Liability Net Asset (Liability) Balance Sheet Location Not Designated as Hedges Commodity $ — $ 152 $ (152) Other current liabilities Commodity — 1 (1) Deferred credits and other liabilities Interest Rate 70 — 70 Other noncurrent assets Interest Rate — 1 (1) Deferred credits and other liabilities Total Not Designated as Hedges $ 70 $ 154 $ (84) Cash Flow Hedges Interest Rate $ — $ 3 $ (3) Other current liabilities Interest Rate — 5 (5) Deferred credits and other liabilities Total Designated Hedges $ — $ 8 $ (8) Total $ 70 $ 162 $ (92) 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 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 September 30, 2021, and the weighted average prices for those contracts: 2021 2022 Fourth Quarter First Quarter Second Quarter Third Quarter Fourth Quarter Crude Oil NYMEX WTI Three-Way Collars Volume (Bbls/day) 40,000 30,000 30,000 10,000 10,000 Weighted average price per Bbl: Ceiling $ 78.05 $ 89.12 $ 89.12 $ 88.44 $ 88.44 Floor $ 50.00 $ 50.00 $ 50.00 $ 50.00 $ 50.00 Sold put $ 40.00 $ 40.00 $ 40.00 $ 40.00 $ 40.00 NYMEX WTI Two-Way Collars Volume (Bbls/day) 40,000 — — — — Weighted average price per Bbl: Ceiling $ 58.92 $ — $ — $ — $ — Floor $ 39.25 $ — $ — $ — $ — NYMEX Roll Basis Swaps Volume (Bbls/day) 40,000 45,000 45,000 45,000 45,000 Weighted average price per Bbl $ 1.15 $ 0.56 $ 0.56 $ 0.56 $ 0.56 Natural Gas Henry Hub (“HH”) Two-Way Collars Volume (MMBtu/day) 200,000 — — — — Weighted average price per MMBtu: Ceiling $ 3.05 $ — $ — $ — $ — Floor $ 2.50 $ — $ — $ — $ — HH Three-Way Collars Volume (MMBtu/day) — 50,000 — — — Weighted average price per MMBtu: Ceiling $ — $ 5.14 $ — $ — $ — Floor $ — $ 3.60 $ — $ — $ — Sold Put $ — $ 2.60 $ — $ — $ — HH Fixed Price Swaps Volume (MMBtu/day) 50,000 — — — — Weighted average price per MMBtu $ 2.88 $ — $ — $ — $ — NGL Fixed Price Ethane Swaps (a) Volume (Bbls/day) 5,000 — — — — Weighted average price per Bbl $ 10.92 $ — $ — $ — $ — Fixed Price Propane Swaps (b) Volume (Bbls/day) 5,000 — — — — Weighted average price per Bbl $ 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 September 30, Nine Months Ended September 30, (In millions) 2021 2020 2021 2020 Unrealized gain (loss) on derivative instruments, net $ 27 $ (36) $ (130) $ 39 Realized gain (loss) on derivative instruments, net (a) $ (106) $ 35 $ (268) $ 92 (a) During the third quarter and first nine months of 2021, net cash paid for settled derivative positions was $108 million and $203 million, respectively. During the third quarter and first nine months of 2020, net cash settled derivative positions was $15 million paid and $76 million received, 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. We recorded a $5 million mark-to-market gain and a $24 million mark-to-market gain within net interest to reflect the change in value of these interest rate swaps during the three and nine months ended September 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 planned to refinance the 2025 Notes. In the second quarter of 2021, 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 September 2021, we fully redeemed these 2025 Notes. See Note 16 for further details. We recorded a $3 million mark-to-market gain and a $34 million mark-to-market gain within net interest to reflect the change in value of these interest rate swaps during the three and nine months ended September 30, 2021. 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 mark-to-market activity within net interest to reflect the change in value of these interest rate swaps during the three and nine months ended September 30, 2021 was immaterial. The following table presents, by maturity date, information about our de-designated forward starting interest rate swap agreements, including the rate. We have the discretion to liquidate the positions should we choose. September 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. Although lease commencement began in September 2021, our first cash lease payment will be February 2022 and the first settlement date for the interest rate swap will be in January 2022. During 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 September 30, 2021, we expect to reclassify $3 million from accumulated other comprehensive income into the income statement over the next twelve months. 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. September 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	9 Months Ended
	Sep. 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 September 30, 2021 and December 31, 2020 by hierarchy level. September 30, 2021 (In millions) Level 1 Level 2 Level 3 Total Derivative instruments, assets Interest rate - not designated as cash flow hedges $ — $ 69 $ — $ 69 Derivative instruments, assets $ — $ 69 $ — $ 69 Derivative instruments, liabilities Commodity (a) $ (32) $ (121) $ — $ (153) Interest rate - designated as cash flow hedges — (8) — (8) Derivative instruments, liabilities $ (32) $ (129) $ — $ (161) Total $ (32) $ (60) $ — $ (92) 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 September 30, 2021 and December 31, 2020. September 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 $ 95 $ 128 $ 72 $ 103 Long-term debt, including current portion (a) 4,729 4,033 6,077 5,431 Deferred credits and other liabilities 51 50 82 76 Total financial liabilities $ 4,875 $ 4,211 $ 6,231 $ 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	9 Months Ended
	Sep. 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 September 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 September 30, 2021, we were in compliance with this covenant with a ratio of 20%. 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. On August 4, 2021, we sent an irrevocable notice of redemption to the trustee to fully redeem our outstanding $900 million 3.85% Senior Notes due 2025 (“2025 Notes”). The 2025 Notes were redeemed on September 7, 2021 and as a result of the redemption, we incurred $102 million in costs related to the make-whole provision premium and the write off of unamortized discount and issuance costs. Long-term debt At September 30, 2021, we had $4.0 billion of total long-term debt outstanding. We currently intend to retire our outstanding long-term debt as it matures. Refer to our 2020 Annual Report on Form 10-K for a listing of our long-term debt maturities.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Stockholders' Equity	Stockholders’ EquityNo share repurchases were made under our share repurchases program during the nine months ended September 30, 2021. We did repurchase $10 million of shares during the nine months ended September 30, 2021 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 September 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. Subsequent to the quarter, we resumed our share repurchase program and repurchased approximately $200 million of shares of our common stock through November 3, 2021. Effective November 3, 2021, our Board of Directors increased our remaining share repurchase program authorization from $1.1 billion to $2.5 billion.

Incentive Based Compensation

Incentive Based Compensation	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Incentive Based Compensation	Incentive Based Compensation Stock options, restricted stock and restricted stock units The following table presents a summary of activity for the first nine months of 2021: Stock Options Restricted Stock & Units Number of Shares Weighted Average Exercise Price Number of Shares & Units Weighted Average Grant Date Fair Value Outstanding at December 31, 2020 6,014,255 $ 21.00 7,851,754 $ 11.72 Granted — $ — 2,306,479 $ 11.21 Exercised/Vested (384,889) $ 7.34 (2,992,724) $ 12.78 Canceled (a) (1,137,109) $ 23.10 (1,037,911) $ 11.78 Outstanding at September 30, 2021 4,492,257 $ 21.64 6,127,598 $ 11.00 (a) Included in canceled are forfeitures related to workforce reductions. Stock-based performance unit awards During the first nine 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 nine 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 performance period, subject to the banking feature described below. The vesting percentage can range from zero to 200%, which is based on performance achieved over a two-year performance period. The performance metric is a predetermined amount of cumulative free cash flow, as defined by the award agreement, generated by the Company over the performance period. The units have a banking feature whereby the stock price valuation and vesting percentage are fixed at no less than 50%, and then again at 100%, if achieved during the performance period. Once those milestones are reached, the vesting percentage will not fall below those banked percentage amounts even if cumulative free cash flow subsequently declines during the performance period, subject to the Compensation Committee’s discretion as described below. The third quarter fair value per unit was $27.52, as calculated by multiplying the estimated vesting percentage by our common stock’s closing stock price on September 30, 2021. 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. As set forth in the award agreement terms, the Compensation Committee retains discretion to reduce the vesting percentage and any bank values and determine free cash flow achievement for these awards.

Defined Benefit Postretirement

Defined Benefit Postretirement Plans	9 Months Ended
	Sep. 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 September 30, Pension Benefits Other Benefits (In millions) 2021 2020 2021 2020 Service cost $ 4 $ 4 $ — $ — Interest cost 2 2 — 1 Expected return on plan assets (2) (2) — — Amortization: – prior service credit (1) (1) (4) (4) – actuarial loss 1 2 1 — Net settlement loss (a) 3 9 — — Net periodic benefit costs (credits) (b) $ 7 $ 14 $ (3) $ (3) Nine Months Ended September 30, Pension Benefits Other Benefits (In millions) 2021 2020 2021 2020 Service cost $ 12 $ 14 $ — $ — Interest cost 6 7 1 2 Expected return on plan assets (6) (7) — — Amortization: – prior service credit (4) (5) (12) (13) – actuarial loss 4 7 2 1 Net settlement loss (a) 8 25 — — Net curtailment gain (c) — (3) — (14) Net periodic benefit costs (credits) (b) $ 20 $ 38 $ (9) $ (24) (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) Net periodic benefit costs (credits) reflects a calculated market-related value of plan assets which recognizes changes in fair value over three years. (c) Related to workforce reductions, which reduced the future expected years of service for employees participating in the plans.. During the first nine months of 2021, we made contributions of $20 million to our funded pension plan. During the first nine months of 2021, we also made payments of $9 million and $7 million related to unfunded pension plans and other postretirement benefit plans. We expect to contribute an additional $2 million in contributions to our funded pension plan this year.

Reclassifications Out of Accumu

Reclassifications Out of Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 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 September 30, Nine Months Ended September 30, (In millions) 2021 2020 2021 2020 Income Statement Line Postretirement and postemployment plans Amortization of prior service credit $ 5 $ 5 $ 16 $ 18 Other net periodic benefit costs Amortization of actuarial loss (2) (2) (6) (8) Other net periodic benefit costs Net settlement loss (3) (9) (8) (25) Other net periodic benefit costs Net curtailment gain — — — 17 Other net periodic benefit costs Interest rate swaps Reclassification of de-designated forward interest rate swaps — — (28) — Net interest and other Total reclassifications of (income) expense, net of tax (a) $ — $ (6) $ (26) $ 2 Net income (loss)

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	9 Months Ended
	Sep. 30, 2021
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information Nine Months Ended September 30, (In millions) 2021 2020 Included in operating activities: Interest paid, net of amounts capitalized $ 185 $ 175 Income taxes paid to (received from) taxing authorities, net of refunds (a) $ 8 $ (50) Noncash investing activities: Increase (decrease) in asset retirement costs $ 49 $ (5) (a) The nine months ended September 30, 2021 and 2020 includes $1 million and $94 million, respectively, related to tax refunds. Other noncash investing activities include accrued capital expenditures for the nine months ended September 30, 2021 and 2020 of $104 million and $81 million, respectively.

Equity Method Investments

Equity Method Investments	9 Months Ended
	Sep. 30, 2021
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments During the periods ended September 30, 2021 and December 31, 2020 our equity method investees were considered related parties. Our investment in our equity method investees are summarized in the following table: (In millions) Ownership as of September 30, 2021 September 30, 2021 December 31, 2020 EGHoldings (a) 60% $ 181 $ 113 Alba Plant LLC (b) 52% 166 168 AMPCO (c) 45% 142 166 Total $ 489 $ 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 September 30, Nine Months Ended September 30, (In millions) 2021 2020 2021 2020 Income data: Revenues and other income $ 325 $ 140 $ 806 $ 423 Income (loss) from operations 188 19 395 (21) Net income (loss) $ 155 $ 12 $ 312 $ (27) Revenues from related parties were $8 million and $24 million for the three and nine months ended September 30, 2021, respectively, and $9 million and $29 million for the three and nine months ended 2020, respectively, with the majority related to EGHoldings in all periods.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 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 September 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 September 30, 2021, we have a $126 million current liability in suspended royalty and working interest revenue, including interest, of which $115 million was included within accounts payable and $11 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 yet-to-be specified and corrective actions, which may increase our development costs, operating costs or both. Given the uncertainty in matters such as these, we are unable to predict the ultimate outcome of this matter at this time. However, we believe that any penalties, mitigation costs or corrective actions that may result from this matter 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, recent historical declines in commodity prices 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 that is the indirect successor in title to certain offshore assets that we previously divested, in the first nine months of 2021 we increased our existing reserve to $37 million related to the anticipated cost to decommission certain wells, pipelines and production facilities. 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 September 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)	9 Months Ended
	Sep. 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 third quarter and first nine 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)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of Income (Loss) Per Share, Basic and Diluted	The per share calculations below exclude 4 million of stock options for each of the three and nine months ended September 30, 2021 and 6 million of stock options for each of the three and nine months ended September 30, 2020 that were antidilutive. Three Months Ended September 30, Nine Months Ended September 30, (In millions, except per share data) 2021 2020 2021 2020 Net income (loss) $ 184 $ (317) $ 297 $ (1,113) Weighted average common shares outstanding 789 790 791 792 Effect of dilutive securities — — — — Weighted average common shares, diluted 789 790 791 792 Net income (loss) per share: Basic $ 0.23 $ (0.40) $ 0.38 $ (1.41) Diluted $ 0.23 $ (0.40) $ 0.38 $ (1.41) Dividends per share $ 0.05 $ — $ 0.12 $ 0.05

Revenues (Tables)

Revenues (Tables)	9 Months Ended
	Sep. 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 nine months ended September 30: United States Three Months Ended September 30, 2021 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 391 $ 425 $ 74 $ 75 $ 19 $ 984 Natural gas liquids 50 63 53 12 5 183 Natural gas 38 29 62 12 3 144 Other 2 — — — 62 64 Revenues from contracts with customers $ 481 $ 517 $ 189 $ 99 $ 89 $ 1,375 Three Months Ended September 30, 2020 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 190 $ 230 $ 65 $ 53 $ 14 $ 552 Natural gas liquids 22 15 28 7 1 73 Natural gas 18 9 33 6 3 69 Other 1 — — — 27 28 Revenues from contracts with customers $ 231 $ 254 $ 126 $ 66 $ 45 $ 722 Nine Months Ended September 30, 2021 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 1,003 $ 1,208 $ 206 $ 229 $ 65 $ 2,711 Natural gas liquids 109 152 127 32 10 430 Natural gas 114 71 212 42 11 450 Other 6 — — — 99 105 Revenues from contracts with customers $ 1,232 $ 1,431 $ 545 $ 303 $ 185 $ 3,696 Nine Months Ended September 30, 2020 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 639 $ 707 $ 181 $ 160 $ 54 $ 1,741 Natural gas liquids 53 28 62 14 4 161 Natural gas 62 22 86 13 7 190 Other 4 — — — 58 62 Revenues from contracts with customers $ 758 $ 757 $ 329 $ 187 $ 123 $ 2,154 International (E.G.) Three Months Ended September 30, Nine Months Ended September 30, (In millions) 2021 2020 2021 2020 Crude oil and condensate $ 56 $ 31 $ 151 $ 96 Natural gas liquids — 1 2 3 Natural gas 6 7 18 22 Other 1 — 2 — Revenues from contracts with customers $ 63 $ 39 $ 173 $ 121

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Three Months Ended September 30, 2021 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 1,375 $ 63 $ — $ 1,438 Net gain (loss) on commodity derivatives (106) — 27 (b) (79) Income (loss) from equity method investments — 86 — 86 Net gain on disposal of assets — — 7 7 Other income — — 1 1 Less costs and expenses: Production 119 12 — 131 Shipping, handling and other operating 209 7 3 219 Exploration 15 — 48 (c) 63 Depreciation, depletion and amortization 499 17 6 522 Impairments — — 13 (d) 13 Taxes other than income 88 — — 88 General and administrative 29 3 38 70 Net interest and other — — 57 (e) 57 Other net periodic benefit costs — — — — Loss on early extinguishment of debt — — 102 (f) 102 Income tax provision (benefit) 5 17 (18) 4 Segment income (loss) $ 305 $ 93 $ (214) $ 184 Total assets $ 15,528 $ 1,071 $ 562 $ 17,161 Capital expenditures (a) $ 303 $ 2 $ 3 $ 308 (a) Includes accruals. (b) Unrealized gain on commodity derivative instruments (See Note 14 ). (c) Includes unproved property impairments of $20 million for Louisiana exploration leases and $16 million related to the disposition of a Permian lease. Also includes $12 million of dry well costs associated with drilled and uncompleted wells, primarily in Permian (See Note 9 ). (d) Includes impairments of $5 million for proved properties in Permian (See Note 10 ) and $8 million associated with decommissioning costs for non-producing long-lived assets in GOM (See Note 10 , Note 11 , and Note 23 ). (e) Includes a $5 million gain on 2022 interest rate swaps and a $3 million gain on 2025 interest rate swaps (See Note 14 ). (f) Represents costs related to a make-whole provision premium and the write off of issuance costs related to the redemption of the 2025 Notes in September 2021 (See Note 16 ). Three Months Ended September 30, 2020 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 722 $ 39 $ — $ 761 Net gain (loss) on commodity derivatives 35 — (36) (b) (1) Income (loss) from equity method investments — 8 (18) (10) Net gain on disposal of assets — — 1 1 Other income 1 1 1 3 Less costs and expenses: Production 118 11 — 129 Shipping, handling and other operating 154 1 28 183 Exploration 21 — 6 27 Depreciation, depletion and amortization 530 19 5 554 Impairments — — 1 1 Taxes other than income 48 — 1 49 General and administrative 25 3 25 53 Net interest and other — — 62 62 Other net periodic benefit costs — — 6 (c) 6 Income tax provision (benefit) (3) 6 4 7 Segment income (loss) $ (135) $ 8 $ (190) $ (317) Total assets $ 16,396 $ 1,104 $ 1,163 $ 18,663 Capital expenditures (a) $ 176 $ — $ 1 $ 177 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 14 ). (c) Includes pension settlement loss of $9 million (See Note 19 ). Nine Months Ended September 30, 2021 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 3,696 $ 173 $ — $ 3,869 Net loss on commodity derivatives (268) — (130) (b) (398) Income (loss) from equity method investments — 179 — 179 Net gain on disposal of assets — — 8 8 Other income 4 3 2 9 Less costs and expenses: Production 343 35 — 378 Shipping, handling and other operating 506 13 19 538 Exploration 54 — 55 (c) 109 Depreciation, depletion and amortization 1,477 54 19 1,550 Impairments — — 60 (d) 60 Taxes other than income 238 — (2) 236 General and administrative 79 9 139 (e) 227 Net interest and other — — 129 (f) 129 Other net periodic benefit credit — — (2) (2) Loss on early extinguishment of debt — — 121 (g) 121 Income tax provision (benefit) 11 33 (20) 24 Segment income (loss) $ 724 $ 211 $ (638) $ 297 Total assets $ 15,528 $ 1,071 $ 562 $ 17,161 Capital expenditures (a) $ 770 $ 4 $ 7 $ 781 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 14 ). (c) Includes unproved property impairments of $20 million for Louisiana exploration leases and $16 million related to the disposition of a lease in Permian. Also includes $12 million of dry well costs associated with drilled and uncompleted wells, primarily in Permian (See Note 9 ). (d) Includes impairments of $24 million for central facilities in Eagle Ford (See Note 10 ), $5 million for proved properties in Permian (See Note 10 ), and $30 million associated with decommissioning costs for non-producing long-lived assets in GOM (See Note 10 , Note 11 , and Note 23 ). (e) Includes $13 million associated with the termination of an aircraft lease agreement and $12 million arising from severance expenses associated with a workforce reduction. (f) Includes a $24 million gain on 2022 interest rate swaps and a $34 million gain on 2025 interest rate swaps (See Note 14 ). (g) 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 and 2025 Notes in September 2021 (See Note 16 ). Nine Months Ended September 30, 2020 (In millions) U.S. Int’l Not Allocated to Segments Total Revenue from contracts with customers $ 2,154 $ 121 $ — $ 2,275 Net gain on commodity derivatives 92 — 39 (b) 131 Loss from equity method investments — (4) (170) (c) (174) Net gain on disposal of assets — — 8 8 Other income 8 5 3 16 Less costs and expenses: Production 375 43 — 418 Shipping, handling and other operating 385 5 42 432 Exploration 75 — 6 81 Depreciation, depletion and amortization 1,716 62 17 1,795 Impairments — — 98 (d) 98 Taxes other than income 144 — 1 145 General and administrative 89 10 118 (e) 217 Net interest and other — — 195 195 Other net periodic benefit credit — — (1) (f) (1) Income tax provision (benefit) (10) 1 (2) (11) Segment income (loss) $ (520) $ 1 $ (594) $ (1,113) Total assets $ 16,396 $ 1,104 $ 1,163 $ 18,663 Capital expenditures (a) $ 874 $ — $ 10 $ 884 (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 $15 million. (f) Includes pension settlement loss of $25 million and pension curtailment gain of $17 million (See Note 19 ).

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Effective Income Tax Rate	For the three and nine months ended September 30, 2021 and 2020, our effective income tax rates were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Effective income tax rate 2 % (2) % 7 % 1 %

Credit Losses (Tables)

Credit Losses (Tables)	9 Months Ended
	Sep. 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) September 30, 2021 December 31, 2020 Beginning balance as of January 1 $ 22 $ 11 Cumulative-effect adjustment — 12 Current period provision (a) 1 22 Current period write offs (1) (13) Recoveries of amounts previously reserved (3) (10) Ending balance $ 19 $ 22

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2021
Inventory Disclosure [Abstract]
Schedule of Inventory, Current	(In millions) September 30, 2021 December 31, 2020 Crude oil and natural gas $ 13 $ 10 Supplies and other items 64 66 Inventories $ 77 $ 76

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	(In millions) September 30, 2021 December 31, 2020 United States $ 14,317 $ 15,156 International 364 414 Corporate 53 68 Net property, plant and equipment $ 14,734 $ 15,638

Impairments (Tables)

Impairments (Tables)	9 Months Ended
	Sep. 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 September 30, 2021 2020 (In millions) Fair Value Impairment Fair Value Impairment Long-lived assets held for use $ — $ 5 $ — $ 1 Asset retirement costs of long-lived assets — 8 — — Equity method investment $ — $ — $ 23 $ 18 Nine Months Ended September 30, 2021 2020 (In millions) Fair Value Impairment Fair Value Impairment Long-lived assets held for use $ — $ 30 $ — $ 3 Asset retirement costs of long-lived assets — 30 — — Goodwill — — — 95 Equity method investment $ — $ — $ 119 $ 170

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	9 Months Ended
	Sep. 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: September 30, (In millions) 2021 2020 Beginning balance as of January 1 $ 254 $ 255 Incurred liabilities, including acquisitions 9 3 Settled liabilities, including dispositions (3) (11) Accretion expense (included in depreciation, depletion and amortization) 9 9 Revisions of estimates 40 (8) Ending balance as of September 30, total $ 309 $ 248 Ending balance as of September 30, short-term $ 23 $ 12

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Supplemental Balance Sheet Information	Balance sheet information related to right-of-use (‘ROU’) assets and lease liabilities was as follows: (In millions) Balance Sheet Location: September 30, 2021 December 31, 2020 ROU assets: Operating leases Other noncurrent assets $ 74 $ 133 Finance leases Other noncurrent assets 35 — Total ROU assets $ 109 $ 133 Lease liabilities: Current liabilities Operating leases Other current liabilities $ 44 $ 70 Finance leases Other current liabilities 5 — Noncurrent liabilities Operating leases Deferred credits and other liabilities 34 67 Finance leases Deferred credits and other liabilities 30 — Total Lease liabilities $ 113 $ 137
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 $ 2 2022 6 2023 6 2024 6 2025 6 Thereafter 56 Total undiscounted cash flows $ 82

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Sep. 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. September 30, 2021 (In millions) Asset Liability Net Asset (Liability) Balance Sheet Location Not Designated as Hedges Commodity $ — $ 152 $ (152) Other current liabilities Commodity — 1 (1) Deferred credits and other liabilities Interest Rate 70 — 70 Other noncurrent assets Interest Rate — 1 (1) Deferred credits and other liabilities Total Not Designated as Hedges $ 70 $ 154 $ (84) Cash Flow Hedges Interest Rate $ — $ 3 $ (3) Other current liabilities Interest Rate — 5 (5) Deferred credits and other liabilities Total Designated Hedges $ — $ 8 $ (8) Total $ 70 $ 162 $ (92) 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 September 30, Nine Months Ended September 30, (In millions) 2021 2020 2021 2020 Unrealized gain (loss) on derivative instruments, net $ 27 $ (36) $ (130) $ 39 Realized gain (loss) on derivative instruments, net (a) $ (106) $ 35 $ (268) $ 92 (a) During the third quarter and first nine months of 2021, net cash paid for settled derivative positions was $108 million and $203 million, respectively. During the third quarter and first nine months of 2020, net cash settled derivative positions was $15 million paid and $76 million received, respectively.
Schedule of Notional Amounts of Outstanding Derivative Positions	The following table sets forth outstanding derivative contracts as of September 30, 2021, and the weighted average prices for those contracts: 2021 2022 Fourth Quarter First Quarter Second Quarter Third Quarter Fourth Quarter Crude Oil NYMEX WTI Three-Way Collars Volume (Bbls/day) 40,000 30,000 30,000 10,000 10,000 Weighted average price per Bbl: Ceiling $ 78.05 $ 89.12 $ 89.12 $ 88.44 $ 88.44 Floor $ 50.00 $ 50.00 $ 50.00 $ 50.00 $ 50.00 Sold put $ 40.00 $ 40.00 $ 40.00 $ 40.00 $ 40.00 NYMEX WTI Two-Way Collars Volume (Bbls/day) 40,000 — — — — Weighted average price per Bbl: Ceiling $ 58.92 $ — $ — $ — $ — Floor $ 39.25 $ — $ — $ — $ — NYMEX Roll Basis Swaps Volume (Bbls/day) 40,000 45,000 45,000 45,000 45,000 Weighted average price per Bbl $ 1.15 $ 0.56 $ 0.56 $ 0.56 $ 0.56 Natural Gas Henry Hub (“HH”) Two-Way Collars Volume (MMBtu/day) 200,000 — — — — Weighted average price per MMBtu: Ceiling $ 3.05 $ — $ — $ — $ — Floor $ 2.50 $ — $ — $ — $ — HH Three-Way Collars Volume (MMBtu/day) — 50,000 — — — Weighted average price per MMBtu: Ceiling $ — $ 5.14 $ — $ — $ — Floor $ — $ 3.60 $ — $ — $ — Sold Put $ — $ 2.60 $ — $ — $ — HH Fixed Price Swaps Volume (MMBtu/day) 50,000 — — — — Weighted average price per MMBtu $ 2.88 $ — $ — $ — $ — NGL Fixed Price Ethane Swaps (a) Volume (Bbls/day) 5,000 — — — — Weighted average price per Bbl $ 10.92 $ — $ — $ — $ — Fixed Price Propane Swaps (b) Volume (Bbls/day) 5,000 — — — — Weighted average price per Bbl $ 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. We have the discretion to liquidate the positions should we choose. September 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. September 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)	9 Months Ended
	Sep. 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 September 30, 2021 and December 31, 2020 by hierarchy level. September 30, 2021 (In millions) Level 1 Level 2 Level 3 Total Derivative instruments, assets Interest rate - not designated as cash flow hedges $ — $ 69 $ — $ 69 Derivative instruments, assets $ — $ 69 $ — $ 69 Derivative instruments, liabilities Commodity (a) $ (32) $ (121) $ — $ (153) Interest rate - designated as cash flow hedges — (8) — (8) Derivative instruments, liabilities $ (32) $ (129) $ — $ (161) Total $ (32) $ (60) $ — $ (92) 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 September 30, 2021 and December 31, 2020. September 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 $ 95 $ 128 $ 72 $ 103 Long-term debt, including current portion (a) 4,729 4,033 6,077 5,431 Deferred credits and other liabilities 51 50 82 76 Total financial liabilities $ 4,875 $ 4,211 $ 6,231 $ 5,610

Incentive Based Compensation (T

Incentive Based Compensation (Tables)	9 Months Ended
	Sep. 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 nine months of 2021: Stock Options Restricted Stock & Units Number of Shares Weighted Average Exercise Price Number of Shares & Units Weighted Average Grant Date Fair Value Outstanding at December 31, 2020 6,014,255 $ 21.00 7,851,754 $ 11.72 Granted — $ — 2,306,479 $ 11.21 Exercised/Vested (384,889) $ 7.34 (2,992,724) $ 12.78 Canceled (a) (1,137,109) $ 23.10 (1,037,911) $ 11.78 Outstanding at September 30, 2021 4,492,257 $ 21.64 6,127,598 $ 11.00 (a) Included in canceled are forfeitures related to workforce reductions.

Defined Benefit Postretiremen_2

Defined Benefit Postretirement Plans (Tables)	9 Months Ended
	Sep. 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 September 30, Pension Benefits Other Benefits (In millions) 2021 2020 2021 2020 Service cost $ 4 $ 4 $ — $ — Interest cost 2 2 — 1 Expected return on plan assets (2) (2) — — Amortization: – prior service credit (1) (1) (4) (4) – actuarial loss 1 2 1 — Net settlement loss (a) 3 9 — — Net periodic benefit costs (credits) (b) $ 7 $ 14 $ (3) $ (3) Nine Months Ended September 30, Pension Benefits Other Benefits (In millions) 2021 2020 2021 2020 Service cost $ 12 $ 14 $ — $ — Interest cost 6 7 1 2 Expected return on plan assets (6) (7) — — Amortization: – prior service credit (4) (5) (12) (13) – actuarial loss 4 7 2 1 Net settlement loss (a) 8 25 — — Net curtailment gain (c) — (3) — (14) Net periodic benefit costs (credits) (b) $ 20 $ 38 $ (9) $ (24) (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) Net periodic benefit costs (credits) reflects a calculated market-related value of plan assets which recognizes changes in fair value over three years. (c) Related to workforce reductions, which reduced the future expected years of service for employees participating in the plans..

Reclassifications Out of Accu_2

Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 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 September 30, Nine Months Ended September 30, (In millions) 2021 2020 2021 2020 Income Statement Line Postretirement and postemployment plans Amortization of prior service credit $ 5 $ 5 $ 16 $ 18 Other net periodic benefit costs Amortization of actuarial loss (2) (2) (6) (8) Other net periodic benefit costs Net settlement loss (3) (9) (8) (25) Other net periodic benefit costs Net curtailment gain — — — 17 Other net periodic benefit costs Interest rate swaps Reclassification of de-designated forward interest rate swaps — — (28) — Net interest and other Total reclassifications of (income) expense, net of tax (a) $ — $ (6) $ (26) $ 2 Net income (loss)

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	9 Months Ended
	Sep. 30, 2021
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Nine Months Ended September 30, (In millions) 2021 2020 Included in operating activities: Interest paid, net of amounts capitalized $ 185 $ 175 Income taxes paid to (received from) taxing authorities, net of refunds (a) $ 8 $ (50) Noncash investing activities: Increase (decrease) in asset retirement costs $ 49 $ (5) (a) The nine months ended September 30, 2021 and 2020 includes $1 million and $94 million, respectively, related to tax refunds.

Equity Method Investments (Tabl

Equity Method Investments (Tables)	9 Months Ended
	Sep. 30, 2021
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Equity Method Investments	During the periods ended September 30, 2021 and December 31, 2020 our equity method investees were considered related parties. Our investment in our equity method investees are summarized in the following table: (In millions) Ownership as of September 30, 2021 September 30, 2021 December 31, 2020 EGHoldings (a) 60% $ 181 $ 113 Alba Plant LLC (b) 52% 166 168 AMPCO (c) 45% 142 166 Total $ 489 $ 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 September 30, Nine Months Ended September 30, (In millions) 2021 2020 2021 2020 Income data: Revenues and other income $ 325 $ 140 $ 806 $ 423 Income (loss) from operations 188 19 395 (21) Net income (loss) $ 155 $ 12 $ 312 $ (27)

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						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)	4			6			4	6
Net income (loss)	$ 184	$ 16	$ 97	$ (317)	$ (750)	$ (46)	$ 297	$ (1,113)
Weighted average common shares outstanding (in shares)	789			790			791	792
Effect of dilutive securities (in shares)	0			0			0	0
Weighted average common shares, diluted (in shares)	789			790			791	792
Net income (loss) per share:
Basic (in dollars per share)	$ 0.23			$ (0.40)			$ 0.38	$ (1.41)
Diluted (in dollars per share)	0.23			(0.40)			0.38	(1.41)
Dividends per share (in dollars per share)	$ 0.05	$ 0.04	$ 0.03	$ 0		$ 0.05	$ 0.12	$ 0.05

Revenues - Narrative (Details)

Revenues - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Receivables from contract with customer	$ 900	$ 572

Revenues - Revenues from Contra

Revenues - Revenues from Contracts with Customers by Product Type and Geographic Areas (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 1,438	$ 761	$ 3,869	$ 2,275
United States E&P
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,375	722	3,696	2,154
United States E&P | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	481	231	1,232	758
United States E&P | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	517	254	1,431	757
United States E&P | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	189	126	545	329
United States E&P | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	99	66	303	187
United States E&P | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	89	45	185	123
United States E&P | Crude oil and condensate
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	984	552	2,711	1,741
United States E&P | Crude oil and condensate | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	391	190	1,003	639
United States E&P | Crude oil and condensate | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	425	230	1,208	707
United States E&P | Crude oil and condensate | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	74	65	206	181
United States E&P | Crude oil and condensate | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	75	53	229	160
United States E&P | Crude oil and condensate | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	19	14	65	54
United States E&P | Natural gas liquids
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	183	73	430	161
United States E&P | Natural gas liquids | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	50	22	109	53
United States E&P | Natural gas liquids | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	63	15	152	28
United States E&P | Natural gas liquids | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	53	28	127	62
United States E&P | Natural gas liquids | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	12	7	32	14
United States E&P | Natural gas liquids | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	5	1	10	4
United States E&P | Natural gas
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	144	69	450	190
United States E&P | Natural gas | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	38	18	114	62
United States E&P | Natural gas | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	29	9	71	22
United States E&P | Natural gas | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	62	33	212	86
United States E&P | Natural gas | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	12	6	42	13
United States E&P | Natural gas | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	3	3	11	7
United States E&P | Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	64	28	105	62
United States E&P | Other | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2	1	6	4
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	62	27	99	58
International E&P | International, Equatorial Guinea (E.G.)
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	63	39	173	121
International E&P | Crude oil and condensate | International, Equatorial Guinea (E.G.)
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	56	31	151	96
International E&P | Natural gas liquids | International, Equatorial Guinea (E.G.)
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	1	2	3
International E&P | Natural gas | International, Equatorial Guinea (E.G.)
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	6	7	18	22
International E&P | Other | International, Equatorial Guinea (E.G.)
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 1	$ 0	$ 2	$ 0

Segment Information (Details)

Segment Information (Details) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2021USD ($)	Jun. 30, 2021USD ($)	Mar. 31, 2021USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2021USD ($)segment	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment							2
Revenues from contracts with customers	$ 1,438			$ 761			$ 3,869	$ 2,275
Net gain (loss) on commodity derivatives	(79)			(1)			(398)	131
Income (loss) from equity method investments	86			(10)			179	(174)
Net gain on disposal of assets	7			1			8	8
Other income	1			3			9	16
Less costs and expenses:
Production	131			129			378	418
Shipping, handling and other operating	219			183			538	432
Exploration	63			27			109	81
Depreciation, depletion and amortization	522			554			1,550	1,795
Impairments	13			1			60	98
Taxes other than income	88			49			236	145
General and administrative	70			53			227	217
Net interest and other	57			62			129	195
Other net periodic benefit costs	0			6			(2)	(1)
Loss on early extinguishment of debt	102			0			121	0
Income tax provision (benefit)	4			7			24	(11)
Segment income (loss)	184	$ 16	$ 97	(317)	$ (750)	$ (46)	297	(1,113)
Total assets	17,161			18,663			17,161	18,663	$ 17,956
Capital expenditures	308			177			781	884
Long-lived assets held for use impairment	5	$ 24		1			30	3
Asset retirement costs of long-lived assets, impairment	8			0			30	0
Goodwill impairment loss						$ 95	0	95
Gulf of Mexico
Less costs and expenses:
Asset retirement costs of long-lived assets, impairment							30
Pension Plan
Less costs and expenses:
Other net periodic benefit costs	3			9			8	25
Pension curtailment gain							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	27			(36)			(130)	39
Income (loss) from equity method investments	0			(18)			0	(170)
Net gain on disposal of assets	7			1			8	8
Other income	1			1			2	3
Less costs and expenses:
Production	0			0			0	0
Shipping, handling and other operating	3			28			19	42
Exploration	48			6			55	6
Depreciation, depletion and amortization	6			5			19	17
Impairments	13			1			60	98
Taxes other than income	0			1			(2)	1
General and administrative	38			25			139	118
Net interest and other	57			62			129	195
Other net periodic benefit costs	0			6			(2)	(1)
Loss on early extinguishment of debt	102						121
Income tax provision (benefit)	(18)			4			(20)	(2)
Segment income (loss)	(214)			(190)			(638)	(594)
Total assets	562			1,163			562	1,163
Capital expenditures	3			1			7	10
Severance costs							12	15
Loss on lease termination							13
Not Allocated to Segments | Permian Basin
Less costs and expenses:
Dry well cost	12						12
Not Allocated to Segments | Eagle Ford
Less costs and expenses:
Long-lived assets held for use impairment							24
Not Allocated to Segments | Gulf of Mexico
Less costs and expenses:
Asset retirement costs of long-lived assets, impairment	8						30
Not Allocated to Segments | Interest Rate Contract, Maturing November 1, 2022 | Not Designated as Hedges
Less costs and expenses:
Loss on interest rate swap	5
Gain on interest rate swap							24
Not Allocated to Segments | Interest Rate Contract, Maturing June 1, 2025 | Not Designated as Hedges
Less costs and expenses:
Gain on interest rate swap	3						34
Not Allocated to Segments | Pension Plan
Less costs and expenses:
Pension settlement loss				9				25
Pension curtailment gain								17
Not Allocated to Segments | Unproved property impairments
Less costs and expenses:
Long-lived assets held for use impairment	20						20
Not Allocated to Segments | Lease | Permian Basin
Less costs and expenses:
Long-lived assets held for use impairment	16						16
Not Allocated to Segments | Proved Property | Permian Basin
Less costs and expenses:
Asset retirement costs of long-lived assets, impairment							5
United States E&P
Segment Reporting Information [Line Items]
Revenues from contracts with customers	1,375			722			3,696	2,154
United States E&P | Eagle Ford
Segment Reporting Information [Line Items]
Revenues from contracts with customers	481			231			1,232	758
United States E&P | Operating Segments
Segment Reporting Information [Line Items]
Revenues from contracts with customers	1,375			722			3,696	2,154
Net gain (loss) on commodity derivatives	(106)			35			(268)	92
Income (loss) from equity method investments	0			0			0	0
Net gain on disposal of assets	0			0			0	0
Other income	0			1			4	8
Less costs and expenses:
Production	119			118			343	375
Shipping, handling and other operating	209			154			506	385
Exploration	15			21			54	75
Depreciation, depletion and amortization	499			530			1,477	1,716
Impairments	0			0			0	0
Taxes other than income	88			48			238	144
General and administrative	29			25			79	89
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)	5			(3)			11	(10)
Segment income (loss)	305			(135)			724	(520)
Total assets	15,528			16,396			15,528	16,396
Capital expenditures	303			176			770	874
Int'l E&P | Operating Segments
Segment Reporting Information [Line Items]
Revenues from contracts with customers	63			39			173	121
Net gain (loss) on commodity derivatives	0			0			0	0
Income (loss) from equity method investments	86			8			179	(4)
Net gain on disposal of assets	0			0			0	0
Other income	0			1			3	5
Less costs and expenses:
Production	12			11			35	43
Shipping, handling and other operating	7			1			13	5
Exploration	0			0			0	0
Depreciation, depletion and amortization	17			19			54	62
Impairments	0			0			0	0
Taxes other than income	0			0			0	0
General and administrative	3			3			9	10
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)	17			6			33	1
Segment income (loss)	93			8			211	1
Total assets	1,071			1,104			1,071	1,104
Capital expenditures	$ 2			$ 0			$ 4	$ 0

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Effective income tax rate	2.00%	(2.00%)	7.00%	1.00%

Credit Losses (Details)

Credit Losses (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance as of January 1	$ 22	$ 11
Current period provision	1	22
Current period write offs	(1)	(13)
Recoveries of amounts previously reserved	(3)	(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	Sep. 30, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Crude oil and natural gas	$ 13	$ 10
Supplies and other items	64	66
Inventories	$ 77	$ 76

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 14,734	$ 14,734	$ 15,638
Exploratory well costs capitalized greater than one year after completion of drilling	125	125	98
Operating Segments | United States
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	14,317	14,317	15,156
Operating Segments | International
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	364	364	414
Corporate
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	53	53	$ 68
Corporate | Permian Basin
Property, Plant and Equipment [Line Items]
Dry well cost	$ 12	$ 12

Impairments (Details)

Impairments (Details) $ in Millions	3 Months Ended					9 Months Ended
	Sep. 30, 2021USD ($)	Jun. 30, 2021USD ($)facility	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Impaired Long-Lived Assets Held and Used [Line Items]
Long-lived assets held for use impairment	$ 5	$ 24	$ 1			$ 30	$ 3
Asset retirement costs of long-lived assets, impairment	8		0			30	0
Goodwill impairment loss					$ 95	0	95
Equity method investment impairment	0		18	$ 152		0	170
Number of impaired facilities | facility		2
Asset retirement obligation	309		248			309	248	$ 254	$ 255
Gulf of Mexico
Impaired Long-Lived Assets Held and Used [Line Items]
Asset retirement costs of long-lived assets, impairment						30
Asset retirement obligation	37					37		$ 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		$ 23			$ 0	$ 119

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance as of January 1			$ 254	$ 255
Incurred liabilities, including acquisitions			9	3
Settled liabilities, including dispositions			(3)	(11)
Accretion expense (included in depreciation, depletion and amortization)			9	9
Revisions of estimates			40	(8)
Ending balance as of September 30, total	$ 309	$ 248	309	248
Asset retirement obligation, current	23	12	23	12
Impairments	8	$ 0	30	$ 0
Gulf of Mexico
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance as of January 1			7
Revisions of estimates			37
Ending balance as of September 30, total	37		37
Asset retirement obligation, current	$ 14		14
Impairments			$ 30

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Sep. 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
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other noncurrent assets	Other noncurrent assets
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other current liabilities	Other current liabilities
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]
ROU assets:
Operating leases	$ 74	$ 133
Finance leases	35	0
Total ROU assets	109	133
Lease liabilities:
Operating leases	44	70
Finance leases	5	0
Operating leases	34	67
Finance leases	30	0
Total Lease liabilities	$ 113	$ 137

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)
Leases [Abstract]
Estimate total project costs	$ 302
Term of contract	5 years
Finance lease ROU asset	$ 32
Finance lease extension term	5 years
Residual value guarantee	100.00%
Weighted average remaining lease term	5 years
Weighted average discount rate, percent	2.25%
Annual payments to be received	$ 6

Leases - Lease Payments to be R

Leases - Lease Payments to be Received (Details) $ in Millions	Sep. 30, 2021USD ($)
Leases [Abstract]
2021	$ 2
2022	6
2023	6
2024	6
2025	6
Thereafter	56
Total undiscounted cash flows	$ 82

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2020	Sep. 30, 2021	Sep. 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	Sep. 30, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Asset	$ 70	$ 39
Liability	162	49
Net Asset (Liability)	(92)	(10)
Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	70	20
Liability	154	33
Net Asset (Liability)	(84)	(13)
Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Asset	0	19
Liability	8	16
Net Asset (Liability)	(8)	3
Commodity | Other current liabilities | Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	0	7
Liability	152	32
Net Asset (Liability)	(152)	(25)
Commodity | Deferred credits and other liabilities | Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	0
Liability	1
Net Asset (Liability)	(1)
Commodity | Other current assets | Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset		3
Liability		1
Net Asset (Liability)		2
Interest Rate | Other current liabilities | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Asset	0
Liability	3
Net Asset (Liability)	(3)
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	5	16
Net Asset (Liability)	(5)	(16)
Interest Rate | Other noncurrent assets | Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	70	10
Liability	0	0
Net Asset (Liability)	$ 70	10
Interest Rate | Other noncurrent assets | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Asset		19
Liability		0
Net Asset (Liability)		$ 19

Derivatives - Outstanding Deriv

Derivatives - Outstanding Derivative Contracts (Details) - Not Designated as Hedges	Sep. 30, 2021MMBTU_per_dayBbls_per_day$ / bbl$ / MMBTU
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 Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	30,000
Derivative, ceiling	89.12
Derivative, floor	50
Derivative, sold put	40
Three-Way Collars - Crude Oil 2022, Second Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	30,000
Derivative, ceiling	89.12
Derivative, floor	50
Derivative, sold put	40
Three-Way Collars - Crude Oil 2022, Third Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	10,000
Derivative, ceiling	88.44
Derivative, floor	50
Derivative, sold put	40
Three-Way Collars - Crude Oil 2022, Fourth Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	10,000
Derivative, ceiling	88.44
Derivative, floor	50
Derivative, sold put	40
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 Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Derivative, ceiling	0
Derivative, floor	0
Two-Way Collars - Crude Oil 2022, Second Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Derivative, ceiling	0
Derivative, floor	0
Two-Way Collars - Crude Oil 2022, Third Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Derivative, ceiling	0
Derivative, floor	0
Two-Way Collars - Crude Oil 2022, Fourth Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Derivative, ceiling	0
Derivative, floor	0
NYMEX Roll Basis Swaps - Crude Oil 2021 Q4
Derivative [Line Items]
Derivative, volume | Bbls_per_day	40,000
NYMEX Roll Basis Swaps - Crude Oil 2021 Q4 | Short
Derivative [Line Items]
Derivative, weighted average price	1.15
NYMEX Roll Basis Swaps - Crude Oil 2022, First Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	45,000
NYMEX Roll Basis Swaps - Crude Oil 2022, First Quarter | Short
Derivative [Line Items]
Derivative, weighted average price	0.56
NYMEX Roll Basis Swaps - Crude Oil 2022, Second Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	45,000
NYMEX Roll Basis Swaps - Crude Oil 2022, Second Quarter | Short
Derivative [Line Items]
Derivative, weighted average price	0.56
NYMEX Roll Basis Swaps - Crude Oil 2022, Third Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	45,000
NYMEX Roll Basis Swaps - Crude Oil 2022, Third Quarter | Short
Derivative [Line Items]
Derivative, weighted average price	0.56
NYMEX Roll Basis Swaps - Crude Oil 2022, Fourth Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	45,000
NYMEX Roll Basis Swaps - Crude Oil 2022, Fourth Quarter | Short
Derivative [Line Items]
Derivative, weighted average price	0.56
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 Quarter
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Derivative, ceiling | $ / MMBTU	0
Derivative, floor | $ / MMBTU	0
Two-Way Collars - Natural Gas 2022, Second Quarter
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Derivative, ceiling | $ / MMBTU	0
Derivative, floor | $ / MMBTU	0
Two-Way Collars - Natural Gas 2022, Third Quarter
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Derivative, ceiling | $ / MMBTU	0
Derivative, floor | $ / MMBTU	0
Two-Way Collars - Natural Gas 2022, Fourth Quarter
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Derivative, ceiling | $ / MMBTU	0
Derivative, floor | $ / MMBTU	0
Three-Way Collars - Natural Gas 2021 Q4
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Derivative, ceiling	0
Derivative, floor	0
Derivative, sold put	0
Three-Way Collars - Natural Gas 2022, First Quarter
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	50,000
Derivative, ceiling	5.14
Derivative, floor	3.60
Derivative, sold put	2.60
Three-Way Collars - Natural Gas 2022, Second Quarter
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Derivative, ceiling	0
Derivative, floor	0
Derivative, sold put	0
Three-Way Collars - Natural Gas 2022, Third Quarter
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Derivative, ceiling	0
Derivative, floor	0
Derivative, sold put	0
Three-Way Collars - Natural Gas 2022, Fourth Quarter
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Derivative, ceiling	0
Derivative, floor	0
Derivative, sold put	0
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 Quarter
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Henry Hub Basis Swaps - Natural Gas 2022, First Quarter | Short
Derivative [Line Items]
Derivative, weighted average price | $ / MMBTU	0
Henry Hub Basis Swaps - Natural Gas 2022, Second Quarter
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Henry Hub Basis Swaps - Natural Gas 2022, Second Quarter | Short
Derivative [Line Items]
Derivative, weighted average price | $ / MMBTU	0
Henry Hub Basis Swaps - Natural Gas 2022, Third Quarter
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Henry Hub Basis Swaps - Natural Gas 2022, Third Quarter | Short
Derivative [Line Items]
Derivative, weighted average price | $ / MMBTU	0
Henry Hub Basis Swaps - Natural Gas 2022, Fourth Quarter
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Henry Hub Basis Swaps - Natural Gas 2022, Fourth Quarter | Short
Derivative [Line Items]
Derivative, weighted average price | $ / MMBTU	0
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 Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Price Ethane Swaps - NGL 2022 First Quarter | Short
Derivative [Line Items]
Derivative, weighted average price	0
Fixed Price Ethane Swaps - NGL 2022 Second Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Price Ethane Swaps - NGL 2022 Second Quarter | Short
Derivative [Line Items]
Derivative, weighted average price	0
Fixed Price Ethane Swaps - NGL 2022 Third Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Price Ethane Swaps - NGL 2022 Third Quarter | Short
Derivative [Line Items]
Derivative, weighted average price	0
Fixed Price Ethane Swaps - NGL 2022 Fourth Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Price Ethane Swaps - NGL 2022 Fourth Quarter | Short
Derivative [Line Items]
Derivative, weighted average price	0
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 Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Price Propane Swaps - NGL 2022, First Quarter | Short
Derivative [Line Items]
Derivative, weighted average price	0
Fixed Price Propane Swaps - NGL 2022, Second Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Price Propane Swaps - NGL 2022, Second Quarter | Short
Derivative [Line Items]
Derivative, weighted average price	0
Fixed Price Propane Swaps - NGL 2022, Third Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Price Propane Swaps - NGL 2022, Third Quarter | Short
Derivative [Line Items]
Derivative, weighted average price	0
Fixed Price Propane Swaps - NGL 2022, Fourth Quarter
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Price Propane Swaps - NGL 2022, Fourth Quarter | 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		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Net settlements of derivative instruments	$ 108	$ 15	$ 203	$ 76
Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivative instruments, net	27	(36)	(130)	39
Realized gain (loss) on derivative instruments, net	$ (106)	$ 35	$ (268)	$ 92

Derivatives - Narrative (Detail

Derivatives - Narrative (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2021	Aug. 04, 2021	Dec. 31, 2020	Dec. 31, 2019
Senior Unsecured Note Due 2025
Derivative Instruments, Gain (Loss) [Line Items]
Long-term debt	$ 900			$ 900	$ 900
Interest rate	3.85%			3.85%	3.85%
Interest Rate Contract, Maturing November 1, 2022 | Not Designated as Hedges | Not Allocated to Segments
Derivative Instruments, Gain (Loss) [Line Items]
Loss on interest rate swap	$ 5
Gain on interest rate swap				$ 24
Interest Rate Contract, Maturing June 1, 2025
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification from AOCI		$ 31
Interest Rate Contract, Maturing June 1, 2025 | Not Designated as Hedges | Not Allocated to Segments
Derivative Instruments, Gain (Loss) [Line Items]
Gain on interest rate swap	3			34
Interest Rate Contract, Maturing September 9, 2026
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification from AOCI		(1)
Amount expected to be reclassified within 12 months				3
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]
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
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	Sep. 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	Sep. 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	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	$ 69	$ 29
Derivative instruments, liabilities	(161)	(39)
Total	(92)	(10)
Interest Rate | Not Designated as Hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	69	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	(153)	(23)
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	0	0
Derivative instruments, liabilities	(32)	0
Total	(32)	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	(32)	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	69	29
Derivative instruments, liabilities	(129)	(39)
Total	(60)	(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	69	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	(121)	(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	Sep. 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	95	72
Long-term debt, including current portion	4,729	6,077
Deferred credits and other liabilities	51	82
Total financial liabilities	4,875	6,231
Carrying Amount
Financial assets
Current assets	12	4
Other noncurrent assets	27	37
Total financial assets	39	41
Financial liabilities
Current liabilities	128	103
Long-term debt, including current portion	4,033	5,431
Deferred credits and other liabilities	50	76
Total financial liabilities	$ 4,211	$ 5,610

Debt - Revolving Credit Facilit

Debt - Revolving Credit Facility (Details) - Revolving Credit Facility	May 28, 2023USD ($)	Sep. 30, 2021USD ($)	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		0.20
Forecast
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 3,000,000,000

Debt - Debt Redemption (Details

Debt - Debt Redemption (Details) - USD ($) $ in Millions	Aug. 04, 2021	Mar. 30, 2021	Sep. 30, 2021
Senior Unsecured Note Due 2022
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
Senior Unsecured Note Due 2025
Debt Instrument [Line Items]
Long-term debt	$ 900		$ 900
Interest rate	3.85%		3.85%
Costs related to make-whole provision premium and write off of unamortized discount and issuance costs	$ 102

Debt - Long-Term Debt (Details)

Debt - Long-Term Debt (Details) $ in Billions	Sep. 30, 2021USD ($)
Debt Disclosure [Abstract]
Outstanding debt	$ 4

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ in Millions	Nov. 03, 2021	Sep. 30, 2021	Mar. 31, 2021	Mar. 31, 2020	Sep. 30, 2021
Equity, Class of Treasury Stock [Line Items]
Shares repurchased (in shares)					0
Value of stock repurchased for restricted stock award tax obligation					$ 10
Stock repurchase program, remaining authorized repurchase amount		$ 1,300			$ 1,300
Shares repurchased, value		$ 0	$ 9	$ 91
Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, remaining authorized repurchase amount	$ 1,100
Shares repurchased, value	200
Stock repurchase program, authorized repurchase amount	$ 2,500

Incentive Based Compensation -

Incentive Based Compensation - Stock Options, Restricted Stock Awards and Restricted Stock Units (Details)	9 Months Ended
	Sep. 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	(1,137,109)
Outstanding, ending (in shares) | shares	4,492,257
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	23.10
Outstanding, ending (in dollars per share) | $ / shares	$ 21.64
Restricted Stock & Units
Number of Shares & Units
Outstanding, beginning (in shares) | shares	7,851,754
Granted (in shares) | shares	2,306,479
Exercised/Vested (in shares) | shares	(2,992,724)
Canceled (in shares) | shares	(1,037,911)
Outstanding, ending (in shares) | shares	6,127,598
Weighted Average Grant Date Fair Value
Outstanding, beginning (in dollars per share) | $ / shares	$ 11.72
Granted (in dollars per share) | $ / shares	11.21
Exercised/Vested (in dollars per share) | $ / shares	12.78
Canceled (in dollars per share) | $ / shares	11.78
Outstanding, ending (in dollars per share) | $ / shares	$ 11

Incentive Based Compensation _2

Incentive Based Compensation - Stock-based Performance Unit Awards (Details)	9 Months Ended
	Sep. 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	$ 27.52

Defined Benefit Postretiremen_3

Defined Benefit Postretirement Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Amortization:
Net settlement loss	$ 0	$ 6	$ (2)	$ (1)
Estimated future contributions over the remainder of the current year	2		2
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	4	12	14
Interest cost	2	2	6	7
Expected return on plan assets	(2)	(2)	(6)	(7)
Amortization:
– prior service credit	(1)	(1)	(4)	(5)
– actuarial loss	1	2	4	7
Net settlement loss	3	9	8	25
Net curtailment gain			0	(3)
Net periodic benefit costs (credits)	7	14	20	38
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	0	1	1	2
Expected return on plan assets	0	0	0	0
Amortization:
– prior service credit	(4)	(4)	(12)	(13)
– actuarial loss	1	0	2	1
Net settlement loss	0	0	0	0
Net curtailment gain			0	(14)
Net periodic benefit costs (credits)	$ (3)	$ (3)	(9)	$ (24)
Payment for other postretirement benefits			7
Funded Plan
Amortization:
Payment for pension benefits			20
Unfunded Plan
Amortization:
Payment for pension benefits			$ 9

Reclassifications Out of Accu_3

Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit (costs) credits	$ 0			$ (6)			$ 2	$ 1
Net interest and other	(57)			(62)			(129)	(195)
Net income (loss)	184	$ 16	$ 97	(317)	$ (750)	$ (46)	297	(1,113)
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			5			16	18
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	(2)			(2)			(6)	(8)
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	(3)			(9)			(8)	(25)
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			0			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	0			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)	$ 0			$ (6)			$ (26)	$ 2

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Included in operating activities:
Interest paid, net of amounts capitalized	$ 185	$ 175
Income taxes paid to (received from) taxing authorities, net of refunds	8	(50)
Noncash investing activities:
Increase (decrease) in asset retirement costs	49	(5)
Proceeds from income tax refunds	1	94
Capital expenditures incurred but not yet paid	$ 104	$ 81

Equity Method Investments - Sch

Equity Method Investments - Schedule of Equity Method Investments (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 489	$ 447
EG Holdings
Schedule of Equity Method Investments [Line Items]
Ownership percentage	60.00%
Equity method investments	$ 181	113
Alba Plant LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage	52.00%
Equity method investments	$ 166	168
AMPCO
Schedule of Equity Method Investments [Line Items]
Ownership percentage	45.00%
Equity method investments	$ 142	$ 166

Equity Method Investments - Sum

Equity Method Investments - Summarized Financial Information (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Schedule of Equity Method Investments [Line Items]
Revenues and other income	$ 1,453			$ 754			$ 3,667	$ 2,256
Income (loss) from operations	347			(242)			569	(930)
Net income (loss)	184	$ 16	$ 97	(317)	$ (750)	$ (46)	297	(1,113)
Consolidated Equity Method Investments
Schedule of Equity Method Investments [Line Items]
Revenues and other income	325			140			806	423
Income (loss) from operations	188			19			395	(21)
Net income (loss)	$ 155			$ 12			$ 312	$ (27)

Equity Method Investments - Nar

Equity Method Investments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Equity Method Investments and Joint Ventures [Abstract]
Revenue from related parties	$ 8	$ 9	$ 24	$ 29
Due from related parties	18		18		$ 24
Due to related parties	$ 6		$ 6		$ 13

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Guarantees recorded	$ 4
Contingent royalty liability	126
Contingent capital and expense receivable, noncurrent	24
Revisions of estimates	40	$ (8)
Asset retirement obligation	309	$ 248	$ 254	$ 255
Gulf of Mexico
Loss Contingencies [Line Items]
Revisions of estimates	37
Asset retirement obligation	37		$ 7
Accounts payable
Loss Contingencies [Line Items]
Contingent royalty liability	115
Other current liabilities
Loss Contingencies [Line Items]
Contingent royalty liability	11
Performance of Equatorial Guinea LNG Operations, S.A.
Loss Contingencies [Line Items]
Guarantor obligations, maximum exposure	91
Performance of Alba Plant LLC.
Loss Contingencies [Line Items]
Guarantor obligations, maximum exposure	$ 25