Marathon Oil (MRO) 10-Q 6 Aug 20 2020 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Jun. 30, 2020	Jul. 31, 2020
Document and Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2020
Document Transition Report	false
Entity File Number	1-1513
Entity Registrant Name (tagged on cover)	Marathon Oil Corporation
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	25-0996816
Entity Address, Address Line One	5555 San Felipe Street,
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77056-2723
City Area Code	(713)
Local Phone Number	629-6600
Title of 12(b) Security	Common Stock, par value $1.00
Trading Symbol	MRO
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		789,439,221
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2020
Amendment Flag	false
Entity Central Index Key	0000101778
Current Fiscal Year End Date	--12-31

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues and other income:
Revenues from contracts with customers	$ 490	$ 1,381	$ 1,514	$ 2,581
Net gain (loss) on commodity derivatives	(70)	16	132	(75)
Income (loss) from equity method investments	(152)	31	(164)	42
Net gain (loss) on disposal of assets	(2)	(8)	7	34
Other income	6	13	13	48
Total revenues and other income	272	1,433	1,502	2,630
Costs and expenses:
Production	129	193	289	380
Shipping, handling and other operating	105	170	249	324
Exploration	26	26	54	85
Depreciation, depletion and amortization	597	605	1,241	1,159
Impairments	0	18	97	24
Taxes other than income	30	79	96	151
General and administrative	88	87	164	181
Total costs and expenses	975	1,178	2,190	2,304
Income (loss) from operations	(703)	255	(688)	326
Net interest and other	(69)	(64)	(133)	(113)
Other net periodic benefit credit	7	2	7	7
Income (loss) before income taxes	(765)	193	(814)	220
Provision (benefit) for income taxes	(15)	32	(18)	(115)
Net income (loss)	$ (750)	$ 161	$ (796)	$ 335
Net income (loss) per share:
Basic (in dollars per share)	$ (0.95)	$ 0.20	$ (1)	$ 0.41
Per diluted share:
Diluted (in dollars per share)	$ (0.95)	$ 0.20	$ (1)	$ 0.41
Weighted average common shares outstanding:
Basic (in shares)	790	813	793	817
Diluted (in shares)	790	814	793	817

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ (750)	$ 161	$ (796)	$ 335
Other comprehensive income (loss), net of tax
Change in actuarial loss and other for postretirement and postemployment plans	(42)	(9)	(42)	(13)
Change in derivative hedges unrecognized loss	(4)	0	(26)	0
Other comprehensive loss	(46)	(9)	(68)	(13)
Comprehensive income (loss)	$ (796)	$ 152	$ (864)	$ 322

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 522	$ 858
Receivables, less reserve of $23 and $11	620	1,122
Inventories	77	72
Derivative assets	79	9
Other current assets	107	74
Total current assets	1,405	2,135
Equity method investments	476	663
Property, plant and equipment, less accumulated depreciation, depletion and amortization of $19,216 and $18,003	16,424	17,000
Goodwill	0	95
Other noncurrent assets	262	352
Total assets	18,567	20,245
Current liabilities:
Accounts payable	696	1,307
Payroll and benefits payable	76	112
Accrued taxes	77	118
Other current liabilities	216	208
Total current liabilities	1,065	1,745
Long-term debt	5,503	5,501
Deferred tax liabilities	171	186
Defined benefit postretirement plan obligations	194	183
Asset retirement obligations	242	243
Deferred credits and other liabilities	217	234
Total liabilities	7,392	8,092
Commitments and contingencies
Stockholders’ Equity
Preferred stock – no shares issued or outstanding (no par value, 26 million shares authorized)	0	0
Common stock:
Issued – 937 million shares (par value $1 per share, 1.925 billion shares authorized at June 30, 2020 and December 31, 2019)	937	937
Held in treasury, at cost – 147 million shares and 141 million shares	(4,087)	(4,089)
Additional paid-in capital	7,143	7,207
Retained earnings	7,145	7,993
Accumulated other comprehensive income	37	105
Total stockholders’ equity	11,175	12,153
Total liabilities and stockholders’ equity	$ 18,567	$ 20,245

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Receivables reserve	$ 23	$ 11
Property, plant and equipment, accumulated depreciation	$ 19,216	$ 18,003
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	26,000,000	26,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	1,925,000,000	1,925,000,000
Common stock, shares issued (in shares)	937,000,000	937,000,000
Held in treasury, shares (in shares)	147,000,000	141,000,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating activities:
Net income	$ (796)	$ 335
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	1,241	1,159
Impairments	97	24
Exploratory dry well costs and unproved property impairments	40	69
Net gain on disposal of assets	(7)	(34)
Deferred income taxes	(14)	(33)
Net (gain) loss on derivative instruments	(132)	75
Net settlements of derivative instruments	57	27
Pension and other post retirement benefits, net	(31)	(41)
Stock-based compensation	28	32
Equity method investments, net	180	12
Changes in:
Current receivables	489	(95)
Inventories	(5)	3
Current accounts payable and accrued liabilities	(456)	(158)
Other current assets and liabilities	46	119
All other operating, net	(27)	(182)
Net cash provided by operating activities	710	1,312
Investing activities:
Additions to property, plant and equipment	(946)	(1,262)
Additions to other assets	12	42
Acquisitions, net of cash acquired	3	0
Disposal of assets, net of cash transferred to the buyer	9	69
Equity method investments - return of capital	7	49
All other investing, net	0	(27)
Net cash used in investing activities	(915)	(1,129)
Financing activities:
Purchases of common stock	(92)	(266)
Dividends paid	(40)	(82)
All other financing, net	1	(2)
Net cash used in financing activities	(131)	(350)
Effect of exchange rate on cash and cash equivalents	0	1
Net decrease in cash and cash equivalents	(336)	(166)
Cash and cash equivalents at beginning of period	858	1,462
Cash and cash equivalents at end of period	522	1,296
Total cash and cash equivalents	$ 522	$ 1,296

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2018	$ 12,128	$ 0	$ 937	$ (3,816)	$ 7,238	$ 7,706	$ 63
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative-effect adjustment	(31)					(31)
Shares issued - stock-based compensation	62			101	(39)
Shares repurchased	(30)			(30)
Stock-based compensation	(50)				(50)
Net income	174					174
Other comprehensive loss	(4)						(4)
Dividends paid (per share amount of $0.05)	(41)					(41)
Ending balance at Mar. 31, 2019	12,208	0	937	(3,745)	7,149	7,808	59
Beginning balance at Dec. 31, 2018	12,128	0	937	(3,816)	7,238	7,706	63
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	335
Other comprehensive loss	(13)
Ending balance at Jun. 30, 2019	12,101	0	937	(3,984)	7,170	7,928	50
Beginning balance at Mar. 31, 2019	12,208	0	937	(3,745)	7,149	7,808	59
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - stock-based compensation	2			(3)	5
Shares repurchased	(236)			(236)
Stock-based compensation	16				16
Net income	161					161
Other comprehensive loss	(9)						(9)
Dividends paid (per share amount of $0.05)	(41)					(41)
Ending balance at Jun. 30, 2019	12,101	0	937	(3,984)	7,170	7,928	50
Beginning balance at Dec. 31, 2019	12,153	0	937	(4,089)	7,207	7,993	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	(46)					(46)
Other comprehensive loss	(22)						(22)
Dividends paid (per share amount of $0.05)	(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	0	937	(4,089)	7,207	7,993	105
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	(796)
Other comprehensive loss	(68)
Ending balance at Jun. 30, 2020	11,175	0	937	(4,087)	7,143	7,145	37
Beginning balance at Mar. 31, 2020	11,958	0	937	(4,059)	7,102	7,895	83
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - stock-based compensation	(8)			(28)	20
Stock-based compensation	21				21
Net income	(750)					(750)
Other comprehensive loss	(46)						(46)
Ending balance at Jun. 30, 2020	$ 11,175	$ 0	$ 937	$ (4,087)	$ 7,143	$ 7,145	$ 37

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Stockholders' Equity [Abstract]
Dividends paid (in dollars per share)	$ 0	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.10

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2020
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 2019 Annual Report on Form 10-K. The results of operations for the second quarter and first six months of 2020 are not necessarily indicative of the results to be expected for the full year.

Accounting Standards

Accounting Standards	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Accounting Standards	Accounting Standards Recently Adopted Financial instruments – credit losses In June 2016, the FASB issued a new accounting standards update that changes the impairment model for trade receivables, net investments in leases, debt securities, loans and certain other instruments. On January 1, 2020 we adopted this standard using the modified retrospective transition method through a cumulative-effect adjustment of $12 million to retained earnings as of the beginning of the adoption period. The standard requires the use of a forward-looking “expected loss” model as opposed to the “incurred loss” model used previously. See Note 8 for more information on credit losses.

Income (Loss) and Dividends per

Income (Loss) and Dividends per Common Share	6 Months Ended
	Jun. 30, 2020
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 7 million of stock options for each of the three and six months ended June 30, 2020 and 6 million of stock options for each of the three and six months ended June 30, 2019 that were antidilutive. Three Months Ended June 30, Six Months Ended June 30, (In millions, except per share data) 2020 2019 2020 2019 Net income (loss) $ (750) $ 161 $ (796) $ 335 Weighted average common shares outstanding 790 813 793 817 Effect of dilutive securities — 1 — — Weighted average common shares, diluted 790 814 793 817 Net income (loss) per share: Basic $ (0.95) $ 0.20 $ (1.00) $ 0.41 Diluted $ (0.95) $ 0.20 $ (1.00) $ 0.41 Dividends per share $ — $ 0.05 $ 0.05 $ 0.10

Dispositions

Dispositions	6 Months Ended
	Jun. 30, 2020
Discontinued Operations and Disposal Groups [Abstract]
Dispositions	Dispositions International Segment In July 2019, we closed on the sale of our U.K. business (Marathon Oil U.K. LLC and Marathon Oil West of Shetlands Limited) for proceeds of approximately $95 million which reflects the assumption by RockRose Energy PLC (the buyer) of the U.K. business’ cash equivalent balance and working capital balance as of year-end 2018. Our income before income taxes relating to our U.K. business for the three and six months ended June 30, 2019, was $18 million and $28 million. In the second quarter of 2019, we closed on the sale of our 15% non-operated interest in the Atrush block in Kurdistan for proceeds of $63 million, before closing adjustments.

Revenues

Revenues	6 Months Ended
	Jun. 30, 2020
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 various international locations. As of June 30, 2020 and December 31, 2019, receivables from contracts with customers, included in receivables, less reserves were $487 million and $837 million, respectively. The following tables present our revenues from contracts with customers disaggregated by product type and geographic areas for the three and six months ended June 30 as follows: United States Three Months Ended June 30, 2020 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 142 $ 147 $ 32 $ 33 $ 7 $ 361 Natural gas liquids 16 3 13 4 1 37 Natural gas 20 5 24 4 1 54 Other 1 — — — 9 10 Revenues from contracts with customers $ 179 $ 155 $ 69 $ 41 $ 18 $ 462 Three Months Ended June 30, 2019 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 350 $ 453 $ 111 $ 77 $ 30 $ 1,021 Natural gas liquids 30 15 31 7 1 84 Natural gas 32 6 36 1 4 79 Other 1 — — — 15 16 Revenues from contracts with customers $ 413 $ 474 $ 178 $ 85 $ 50 $ 1,200 Six Months Ended June 30, 2020 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 449 $ 477 $ 116 $ 107 $ 40 $ 1,189 Natural gas liquids 31 13 34 7 3 88 Natural gas 44 13 53 7 4 121 Other 3 — — — 31 34 Revenues from contracts with customers $ 527 $ 503 $ 203 $ 121 $ 78 $ 1,432 Six Months Ended June 30, 2019 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 668 $ 825 $ 188 $ 141 $ 58 $ 1,880 Natural gas liquids 65 25 53 15 3 161 Natural gas 66 18 81 7 10 182 Other 3 — — — 36 39 Revenues from contracts with customers $ 802 $ 868 $ 322 $ 163 $ 107 $ 2,262 International Three Months Ended June 30, 2020 (In millions) E.G. Crude oil and condensate $ 20 Natural gas liquids 1 Natural gas 7 Revenues from contracts with customers $ 28 Three Months Ended June 30, 2019 (In millions) E.G. U.K. Other Int’l Total Crude oil and condensate $ 101 $ 51 $ 9 $ 161 Natural gas liquids 1 — — 1 Natural gas 9 4 — 13 Other — 6 — 6 Revenues from contracts with customers $ 111 $ 61 $ 9 $ 181 Six Months Ended June 30, 2020 (In millions) E.G. Crude oil and condensate $ 65 Natural gas liquids 2 Natural gas 15 Revenues from contracts with customers $ 82 Six Months Ended June 30, 2019 (In millions) E.G. U.K. Other Int’l Total Crude oil and condensate $ 148 $ 107 $ 19 $ 274 Natural gas liquids 2 1 — 3 Natural gas 16 12 — 28 Other — 14 — 14 Revenues from contracts with customers $ 166 $ 134 $ 19 $ 319

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2020
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 which 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 property, goodwill, and equity method investments, unrealized gains or losses on commodity derivative instruments, effects of pension settlements and curtailments, or other items (as determined by the chief operating decision maker (“CODM”)) are not allocated to operating segments. Three Months Ended June 30, 2020 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 462 $ 28 $ — $ 490 Net gain (loss) on commodity derivatives 26 — (96) (b) (70) Loss from equity method investments — — (152) (c) (152) Net loss on disposal of assets — — (2) (2) Other income 3 2 1 6 Less costs and expenses: Production 114 15 — 129 Shipping, handling and other operating 91 1 13 105 Exploration 26 — — 26 Depreciation, depletion and amortization 569 22 6 597 Taxes other than income 30 — — 30 General and administrative 32 3 53 (d) 88 Net interest and other — — 69 69 Other net periodic benefit credit — — (7) (e) (7) Income tax benefit (6) (5) (4) (15) Segment loss $ (365) $ (6) $ (379) $ (750) Total assets $ 16,791 $ 1,144 $ 632 $ 18,567 Capital expenditures (a) $ 137 $ — $ 2 $ 139 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 15 ). (c) Partial impairment of investment in equity method investee (See N ot e 2 3 ). (d) Includes severance expenses associated with workforce reductions of $13 million. (e) Includes pension settlement loss of $14 million and pension curtailment gain of $17 million (See N ote 2 0 ). Three Months Ended June 30, 2019 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 1,200 $ 181 $ — $ 1,381 Net gain on commodity derivatives 5 — 11 (b) 16 Income from equity method investments — 31 — 31 Net loss on disposal of assets — — (8) (c) (8) Other income 4 2 7 13 Less costs and expenses: Production 147 46 — 193 Shipping, handling and other operating 147 10 13 170 Exploration 26 — — 26 Depreciation, depletion and amortization 561 38 6 605 Impairments — — 18 (d) 18 Taxes other than income 79 — — 79 General and administrative 31 8 48 87 Net interest and other — — 64 64 Other net periodic benefit credit — (1) (1) (2) Income tax provision 3 17 12 32 Segment income (loss) $ 215 $ 96 $ (150) $ 161 Total assets $ 17,539 $ 2,913 $ 830 $ 21,282 Capital expenditures (a) $ 686 $ 10 $ 5 $ 701 (a) Includes accruals. (b) Unrealized gain on commodity derivative instruments (See Note 15 ). (c) Primarily related to the sale of certain non-core proved properties in our International segment (see No te 4 ). (d) Primarily as a result of the anticipated sale of non-core proved properties in our United States segment (See Note 11 ). Six Months Ended June 30, 2020 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 1,432 $ 82 $ — $ 1,514 Net gain on commodity derivatives 57 — 75 (b) 132 Loss from equity method investments — (12) (152) (c) (164) Net gain on disposal of assets — — 7 7 Other income 7 4 2 13 Less costs and expenses: Production 257 32 — 289 Shipping, handling and other operating 231 4 14 249 Exploration 54 — — 54 Depreciation, depletion and amortization 1,186 43 12 1,241 Impairments — — 97 (d) 97 Taxes other than income 96 — — 96 General and administrative 64 7 93 (e) 164 Net interest and other — — 133 133 Other net periodic benefit credit — — (7) (f) (7) Income tax benefit (7) (5) (6) (18) Segment loss $ (385) $ (7) $ (404) $ (796) Total assets $ 16,791 $ 1,144 $ 632 $ 18,567 Capital expenditures (a) $ 698 $ — $ 9 $ 707 (a) Includes accruals. (b) Unrealized gain on commodity derivative instruments (See Note 15 ). (c) Partial impairment of investment in equity method investee (See N ote 23 ). (d) Includes the full impairment of the International reporting unit goodwill of $95 million (See N ote 14 ). (e) Includes severance expenses associated with workforce reductions of $13 million. (f) Includes pension settlement loss of $16 million and pension curtailment gain of $17 million (See Note 20 ). Six Months Ended June 30, 2019 (In millions) U.S. Int’l Not Allocated to Segments Total Revenue from contracts with customers $ 2,262 $ 319 $ — $ 2,581 Net gain (loss) on commodity derivatives 27 — (102) (b) (75) Income from equity method investments — 42 — 42 Net gain on disposal of assets — — 34 (c) 34 Other income 5 5 38 (d) 48 Less costs and expenses: Production 286 96 (2) 380 Shipping, handling and other operating 287 23 14 324 Exploration 85 — — 85 Depreciation, depletion and amortization 1,075 72 12 1,159 Impairments — — 24 (e) 24 Taxes other than income 153 — (2) 151 General and administrative 60 15 106 181 Net interest and other — — 113 113 Other net periodic benefit credit — (3) (4) (7) Income tax provision (benefit) 1 6 (122) (f) (115) Segment income (loss) $ 347 $ 157 $ (169) $ 335 Total assets $ 17,539 $ 2,913 $ 830 $ 21,282 Capital expenditures (a) $ 1,292 $ 15 $ 8 $ 1,315 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 15 ). (c) Primarily related to the sale of our working interest in the Droshky field (Gulf of Mexico). (d) Primarily related to the indemnification of certain tax liabilities in connection with the 2010-2011 Federal Tax Audit (See Note 7 ). (e) Primarily as a result of anticipated sales of certain non-core proved properties in our International and United States segments. (f) Primarily relates to the settlement of the 2010-2011 Federal Tax Audit (See Note 7 ).

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2020
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 6 . For the three and six months ended June 30, 2020 and 2019, our effective income tax rates were as follows: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Effective income tax rate (a) 2 % 17 % 2 % (52) % (a) In all periods presented, we maintained our valuation allowance on our net federal deferred tax assets in the U.S. The following items caused the effective income tax rates to be different from our U.S. statutory tax rate of 21% for 2020 and 2019: • For the three and six months ended June 30, 2020, the income tax rate was reduced below the statutory rate due to the valuation allowance on our net federal deferred tax assets in the U.S., which resulted in no federal tax benefit on the U.S. loss. • For the three and six months ended June 30, 2019, the mix of pre-tax income in our international operations reduced the annual effective tax rate below the statutory tax rate . Income tax rates for the six months ended June 30, 2019 were also impacted by the settlement of the 2010-2011 U.S. Federal Tax Audit (“IRS Audit”) in the first quarter of 2019, resulting in a tax benefit of $126 million. Additionally, in the first quarter of 2019, we recorded a non-cash deferred tax benefit of $18 million in the U.K. related to an internal restructuring. These two items are discrete to the first six months of 2019. Excluding these discrete adjustments, the effective income tax rate for the first six months of 2019 was an expense of 13%. In the first quarter of 2020, the U.S. enacted the Coronavirus Aid, Relief, and Economic Security Act , commonly referred to as the CARES Act. This legislation included certain provisions which accelerate income tax refunds, and as a result, in the first quarter of 2020, long term receivable balances related to alternative minimum tax credits were classified as short term. Subsequent to June 30, 2020, we received an $89 million cash refund related to these alternative minimum tax credits and interest.

Credit Losses

Credit Losses	6 Months Ended
	Jun. 30, 2020
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 and reasonable and supportable forecasts of future economic conditions. We are exposed to credit losses through the receivables generated from sales of crude oil, NGLs and natural gas to our customers. When dealing with the commodity purchasers, we conduct a credit review to assess each counterparty’s ability to pay. The credit review considers our expected billing exposure, timing for payment and the counterparty’s established credit rating with the rating agencies or our internal assessment of the counterparty’s creditworthiness based on our analysis of their financial statements. Our evaluation also considers contract terms and other factors, such as country and/or political risk. A credit limit is established for each counterparty based on the outcome of this review. We may require a bank letter of credit or a prepayment to mitigate credit risk. We monitor our ongoing credit exposure through active review of counterparty balances against contract terms and due dates. The expected credit losses related to receivables with the commodity purchasers were determined using the weighted average probability of default method. We also collect revenues from our non-operated joint properties where other oil and gas exploration and production companies operate the properties and market our share of production and remit payments to us. The current expected credit losses related to these receivables were determined using the loss rate method applied to aging pools. We are exposed to credit losses from joint interest billings to other joint interest owners for properties we operate. For this group of receivables, the expected credit losses are determined using the loss rate method applied to aging pools. Our counterparties in this group include numerous large, mid-size and small oil and gas exploration and production companies. Although we may have the ability to withhold future revenue disbursements to recover any non-payment of joint interest billings or require a prepayment of future costs through cash calls, our credit loss exposure with this group is more significant due to inherent ownership or billing adjustments. Also, some of our counterparties may experience liquidity problems and may not be able to meet their financial obligations to us. We expect that liquidity problems will increase in the future as a result of the recent demand and pricing decline for hydrocarbons. Our current-period provision reflects the anticipated effects caused by the recent market deterioration. Changes in the allowance for doubtful accounts balance for the six months ended were as follows: (In millions) June 30, 2020 Beginning balance as of January 1 $ 11 Cumulative-effect adjustment 12 Current period provision (a) 6 Recoveries of amounts previously written off (6) Ending balance as of June 30 $ 23

Inventories

Inventories	6 Months Ended
	Jun. 30, 2020
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. The continued volatility and future decline in crude oil and natural gas prices could affect the value of our inventories and result in future impairments. (In millions) June 30, 2020 December 31, 2019 Crude oil and natural gas $ 9 $ 10 Supplies and other items 68 62 Inventories $ 77 $ 72

Property, Plant and Equipment

Property, Plant and Equipment	6 Months Ended
	Jun. 30, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment (In millions) June 30, 2020 December 31, 2019 United States $ 15,899 $ 16,427 International 449 493 Corporate 76 80 Net property, plant and equipment $ 16,424 $ 17,000 We had no exploratory well costs capitalized greater than one year as of June 30, 2020 and December 31, 2019.

Impairments

Impairments	6 Months Ended
	Jun. 30, 2020
Impairment Expense [Abstract]
Impairments	Impairments During the first quarter of 2020, a global pandemic caused a substantial deterioration in the worldwide demand of hydrocarbons. The decreased demand, when coupled with an oversupplied market, caused a corresponding deterioration in hydrocarbon prices. We reviewed our long-lived assets for indicators of impairment during the first quarter by conducting a sensitivity analysis of the most impactful inputs to their undiscounted cash flows, including commodity prices, capital spend and reductions in production volumes to correspond with lower capital spending. Our review concluded that the carrying amounts of our long-lived assets are recoverable; however, further deterioration or a more sustained decline of commodity prices may result in impairment charges in future periods. We also reviewed our equity method investments for indicators of impairment. Equity method investments are assessed for impairment whenever changes in the facts and circumstances indicate a loss in value may have occurred. When a loss in value occurs that is deemed other than temporary, the carrying value of the equity method investment is written down to fair value. Our first quarter review concluded that any potential losses in values of our equity method investments were temporary because the underlying declines in both commodity prices and demand did not materially manifest until early March. However, during the second quarter of 2020, we did recognize an impairment related to one of our equity method investees as noted in the table below. The following table summarizes impairment charges of proved properties, goodwill and equity method investments and their corresponding fair values. Three Months Ended June 30, 2020 2019 (In millions) Fair Value Impairment Fair Value Impairment Long-lived assets held for use $ — $ — $ 19 $ 18 Equity method investment $ 142 $ 152 N/A $ — Six Months Ended June 30, 2020 2019 (In millions) Fair Value Impairment Fair Value Impairment Long-lived assets held for use $ — $ 2 $ 56 $ 24 Goodwill $ — $ 95 N/A $ — Equity method investment $ 142 $ 152 N/A $ — • 2020 – During the second quarter of 2020, the continuation of the depressed commodity prices caused us to perform a review of our equity method investments. Our review concluded that a loss of our investment value in one of our equity method investees was other than temporary. We recorded an impairment of $152 million based on the difference between our carrying value and the fair value of our investment. Our remaining investments in equity method investees did not experience losses in value that caused the fair values to be below their carrying values. We estimated the fair value of our equity method investment using an income approach, specifically utilizing a discounted cash flow analysis. The estimated fair value was based on significant inputs not observable in the market, such as the amount of gas processed by the plant, future commodity prices, forecasted operating expenses, discount rate, and estimated cash returned to shareholders. Collectively, these inputs represent Level 3 measurements. The impairment was recognized in income (loss) from equity method investments in our consolidated statements of income. The impairment caused us to incur a basis differential between the net book value of our investment and the amount of our underlying share of equity in the investee’s net assets. The amount of this basis differential is $126 million and will be accreted into income over the next 6.5 years, which is consistent with the remaining useful life of the investee’s primary assets. Impairments for the six months ended June 30, 2020 also included $95 million of goodwill impairment in the International reporting unit. See No te 1 4 for further information. • 2019 – During the six months ended June 30, 2019, we recorded proved property impairments of $24 million, as a result of the anticipated sales proceeds for certain non-core proved properties in our United States segment and the sale of our non-operated interest in the Atrush block (Kurdistan) in our International segment. The related fair value was measured using the market approach, based upon anticipated sales proceeds less costs to sell which resulted in a Level 2 classification. See Note 4 for further information.

Asset Retirement Obligations

Asset Retirement Obligations	6 Months Ended
	Jun. 30, 2020
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 for the six months ended June 30 were as follows: June 30, (In millions) 2020 2019 Beginning balance as of January 1 $ 255 $ 1,145 Incurred liabilities, including acquisitions 2 18 Settled liabilities, including dispositions (3) (129) Accretion expense (included in depreciation, depletion and amortization) 6 26 Revisions of estimates (8) 11 Held for sale — (864) Ending balance as of June 30 $ 252 $ 207 June 30, 2020 • Ending balance includes $10 million classified as short-term at June 30, 2020. June 30, 2019 • Settled liabilities primarily relate to the sale of our working interest in the Droshky field (Gulf of Mexico), which closed during the first quarter of 2019. • Held for sale includes the asset retirement obligations of $966 million associated with the sale of our U.K. business, which was partially offset by settled liabilities for dispositions primarily related to the Droshky field in the first quarter of 2019. See Note 4 for discussion of the divestitures in further detail. • Ending balance includes $18 million classified as short-term at June 30, 2019.

Leases

Leases	6 Months Ended
	Jun. 30, 2020
Leases [Abstract]
Leases	Leases We enter into various lease agreements to support our operations including drilling rigs, well fracturing equipment, compressors, buildings, aircraft, vessels, vehicles and miscellaneous field equipment. We primarily act as a lessee in these transactions and all of our existing leases are classified as either short-term or long-term operating leases. Supplemental balance sheet information related to leases was as follows: (In millions) June 30, 2020 Operating Leases: Balance Sheet Location: Right-of-use asset Other noncurrent assets $ 153 Current portion of long-term lease liability Other current liabilities $ 83 Long-term lease liability Deferred credits and other liabilities $ 74 Our wholly-owned subsidiary, Marathon E.G. Production Limited, is a lessor for residential housing in Equatorial Guinea, which is occupied by EGHoldings, a related party equity method investee – see Note 24 . 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 2020 $ 3 2021 6 2022 6 2023 6 2024 6 Thereafter 60 Total undiscounted cash flows $ 87 In 2018, we signed an agreement with an owner/lessor to construct and lease a new build-to-suit office building in Houston, Texas. The new Houston office location is expected to be completed in 2021. The lessor and other participants are providing financing for up to $380 million, to fund the estimated project costs. As of June 30, 2020, project costs incurred totaled approximately $87 million, including land acquisition and construction costs. The initial lease term is five years and will commence once construction is substantially complete and the new Houston office is ready for occupancy. 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 approximately 89% of the total acquisition and construction costs.
Leases	Leases We enter into various lease agreements to support our operations including drilling rigs, well fracturing equipment, compressors, buildings, aircraft, vessels, vehicles and miscellaneous field equipment. We primarily act as a lessee in these transactions and all of our existing leases are classified as either short-term or long-term operating leases. Supplemental balance sheet information related to leases was as follows: (In millions) June 30, 2020 Operating Leases: Balance Sheet Location: Right-of-use asset Other noncurrent assets $ 153 Current portion of long-term lease liability Other current liabilities $ 83 Long-term lease liability Deferred credits and other liabilities $ 74 Our wholly-owned subsidiary, Marathon E.G. Production Limited, is a lessor for residential housing in Equatorial Guinea, which is occupied by EGHoldings, a related party equity method investee – see Note 24 . 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 2020 $ 3 2021 6 2022 6 2023 6 2024 6 Thereafter 60 Total undiscounted cash flows $ 87 In 2018, we signed an agreement with an owner/lessor to construct and lease a new build-to-suit office building in Houston, Texas. The new Houston office location is expected to be completed in 2021. The lessor and other participants are providing financing for up to $380 million, to fund the estimated project costs. As of June 30, 2020, project costs incurred totaled approximately $87 million, including land acquisition and construction costs. The initial lease term is five years and will commence once construction is substantially complete and the new Houston office is ready for occupancy. 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 approximately 89% of the total acquisition and construction costs.

Goodwill

Goodwill	6 Months Ended
	Jun. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill As of December 31, 2019, our consolidated balance sheet included goodwill of $95 million in the International reporting unit. 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. This demand loss resulted in a significant decline in hydrocarbon prices. The commensurate decline in our market capitalization during the first quarter 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. Key assumptions to the income approach include future liquid hydrocarbon and natural gas pricing, estimated quantities of liquid hydrocarbons and natural gas proved and probable reserves, estimated timing of production, discount rates, future capital requirements, operating expenses and tax rates. The assumptions used in the income approach are consistent with those that management uses to make business decisions. 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. June 30, (In millions) 2020 2019 Beginning balance as of January 1, gross $ 95 $ 97 Less: accumulated impairments — — Beginning balance, net 95 97 Dispositions — (2) Impairment (95) — Ending balance as of June 30, net $ — $ 95

Derivatives

Derivatives	6 Months Ended
	Jun. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives For further information regarding the fair value measurement of derivative instruments, see Note 16 . All of our commodity derivatives are subject to enforceable master netting arrangements or similar agreements under which we report net amounts. The following tables present the gross fair values of derivative instruments and the reported net amounts along with where they appear on the consolidated balance sheets. June 30, 2020 (In millions) Asset Liability Net Asset (Liability) Balance Sheet Location Not Designated as Hedges Commodity $ 100 $ 21 $ 79 Derivative assets Total Not Designated as Hedges $ 100 $ 21 $ 79 Cash Flow Hedges Interest Rate $ — $ 26 $ (26) Deferred credits and other liabilities Interest Rate 2 — 2 Other noncurrent assets Total Designated Hedges $ 2 $ 26 $ (24) Total $ 102 $ 47 $ 55 December 31, 2019 (In millions) Asset Liability Net Asset (Liability) Balance Sheet Location Not Designated as Hedges Commodity $ 9 $ 1 $ 8 Derivative assets Commodity 1 — 1 Other noncurrent assets Commodity — 5 (5) Other current liabilities Total Not Designated as Hedges $ 10 $ 6 $ 4 Cash Flow Hedges Interest Rate $ 2 $ — $ 2 Other noncurrent assets Total Designated Hedges $ 2 $ — $ 2 Total $ 12 $ 6 $ 6 Derivatives Not Designated as Hedges We have entered into multiple crude oil and natural gas derivatives indexed to the respective indices as noted in the table below, related to a portion of our forecasted United States sales through 2021. These derivatives consist of three-way collars, two-way collars, fixed price swaps, basis swaps and NYMEX roll basis swaps. Three-way collars consist of a sold call (ceiling), a purchased put (floor) and a sold put. The ceiling price is the maximum we will receive for the contract volumes; the floor is the minimum price we will receive, unless the market price falls below the sold put strike price. In this case, we receive the NYMEX WTI price plus the difference between the floor and the sold put price. Two-way collars only consist of a sold call (ceiling) and a purchased put (floor). These crude oil and natural gas derivatives were not designated as hedges. The following table sets forth outstanding derivative contracts as of June 30, 2020, and the weighted average prices for those contracts: 2020 2021 Third Quarter Fourth Quarter Full Year Crude Oil NYMEX WTI Three-Way Collars Volume (Bbls/day) 80,000 80,000 — Weighted average price per Bbl: Ceiling $ 64.40 $ 64.40 $ — Floor $ 55.00 $ 55.00 $ — Sold put $ 48.00 $ 48.00 $ — NYMEX WTI Two-Way Collars Volume (Bbls/day) 33,478 — — Weighted average price per Bbl: Ceiling $ 40.47 $ — $ — Floor $ 30.98 $ — $ — Fixed Price WTI Swaps Volume (Bbls/day) 10,000 — — Weighted average price per Bbl $ 32.77 $ — $ — Basis Swaps - Argus WTI Midland (a) Volume (Bbls/day) 15,000 15,000 — Weighted average price per Bbl $ (0.94) $ (0.94) $ — Basis Swaps - NYMEX WTI / ICE Brent (b) Volume (Bbls/day) 5,000 5,000 808 Weighted average price per Bbl $ (7.24) $ (7.24) $ (7.24) NYMEX Roll Basis Swaps Volume (Bbls/day) 60,000 30,000 — Weighted average price per Bbl $ (1.58) $ (0.81) $ — Natural Gas Two-Way Collars Volume (MMBtu/day) — — 62,329 Weighted average price per MMBtu: Ceiling $ — $ — $ 3.07 Floor $ — $ — $ 2.44 Basis Swaps - WAHA / HH (c) Volume (MMBtu/day) 10,000 10,000 — Weighted average price per MMBtu $ (0.37) $ (0.37) $ — (a) The basis differential price is indexed against Argus WTI Midland. (b) The basis differential price is indexed against Intercontinental Exchange (“ICE”) Brent and NYMEX WTI. (c) The basis differential price is indexed against Waha and NYMEX Henry Hub. The following table sets forth outstanding derivative contracts entered into between July 1 and August 5, 2020, and the weighted average prices for those contracts: 2020 2021 Third Quarter Fourth Quarter Full Year Crude Oil NYMEX WTI Two-Way Collars Volume (Bbls/day) 3,261 10,000 10,000 Weighted average price per Bbl: Ceiling $ 48.00 $ 48.65 $ 52.37 Floor $ 36.50 $ 37.00 $ 35.00 Natural Gas Two-Way Collars Volume (MMBtu/day) 66,304 150,000 50,000 Weighted average price per MMBtu: Ceiling $ 2.49 $ 2.62 $ 2.93 Floor $ 2.00 $ 2.13 $ 2.40 NGL Fixed Price Ethane Swaps Volume (MMBtu/day) 7,304 10,000 — Weighted average price per Bbl $ 8.78 $ 8.78 $ — The mark-to-market impact and settlement of our commodity derivative instruments appears in the table below and is reflected in net gain (loss) on commodity derivatives in the consolidated statements of income. Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Mark-to-market gain (loss) $ (96) $ 11 $ 75 $ (102) Net settlements of commodity derivative instruments $ 26 $ 5 $ 57 $ 27 Derivatives Designated as Cash Flow Hedges During 2020, we entered into forward starting interest rate swaps with a notional amount of $500 million to hedge variations in cash flows arising from fluctuations in the London Interbank Offered Rate (“LIBOR”) benchmark interest rate related to forecasted interest payments of a future debt issuance in 2022; and an additional $300 million of notional for our future debt issuance in 2025. We expect to refinance both of the debt maturities in 2022 and 2025. The swaps will terminate on or prior to the refinancing of the debt and the final value will be reclassified from accumulated other comprehensive income into earnings with each future interest payment. Subsequent to June 30, 2020, we entered into additional forward starting interest rate swaps with a notional amount of $50 million and a weighted average rate of 0.90% to hedge variations in cash flows related to the same LIBOR interest rate for our debt due in 2025. During 2019, we entered into forward starting interest rate swaps with a total notional amount of $320 million to hedge variations in cash flows related to the 1-month LIBOR component of future lease payments of our future Houston office. These swaps will settle monthly on the same day the lease payment is made with the first swap settlement occurring in January 2022. We expect the first lease payment to commence sometime in the period from December 2021 to May 2022. The last swap will mature on September 9, 2026. See Note 13 for further details regarding the lease of the new Houston office. The following table presents, by maturity date, information about our interest rate swap agreements, including the weighted average LIBOR-based, fixed rate. June 30, 2020 December 31, 2019 Maturity Date Aggregate Notional Amount (in millions) Weighted Average, LIBOR Aggregate Notional Amount (in millions) Weighted Average, LIBOR November 1, 2022 $ 500 0.99 % $ — — % June 1, 2025 $ 300 0.96 % $ — — % September 9, 2026 $ 320 1.51 % $ 320 1.51 % At June 30, 2020, accumulated other comprehensive income included deferred losses of $24 million related to forward starting interest rate swaps. No amounts related to these swaps are expected to impact the consolidated statements of income in the next 12 months.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair Values – Recurring The following tables present assets and liabilities accounted for at fair value on a recurring basis as of June 30, 2020 and December 31, 2019 by hierarchy level. June 30, 2020 (In millions) Level 1 Level 2 Level 3 Total Derivative instruments, assets Commodity (a) $ — $ 88 $ — $ 88 Interest rate — 2 — 2 Derivative instruments, assets $ — $ 90 $ — $ 90 Derivative instruments, liabilities Commodity (a) $ (9) $ — $ — $ (9) Interest rate — (26) — (26) Derivative instruments, liabilities $ (9) $ (26) $ — $ (35) Total $ (9) $ 64 $ — $ 55 December 31, 2019 (In millions) Level 1 Level 2 Level 3 Total Derivative instruments, assets Commodity (a) $ — $ 7 $ — $ 7 Interest rate — 2 — 2 Derivative instruments, assets $ — $ 9 $ — $ 9 Derivative instruments, liabilities Commodity (a) $ (3) $ — $ — $ (3) Derivative instruments, liabilities $ (3) $ — $ — $ (3) Total $ (3) $ 9 $ — $ 6 (a) Derivative instruments are recorded on a net basis in our consolidated balance sheet. See Note 15 . 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 15 for detail on the forward starting interest rate swaps. Fair Value Estimates – Goodwill See Note 14 for detail information relating to goodwill. Fair Values – Nonrecurring See Note 11 for detail on our fair values related to impairments. Fair Values – Financial Instruments Our current assets and liabilities include financial instruments, the most significant of which are receivables, the current portion of our long-term debt and payables. We believe the carrying values of our receivables and payables approximate fair value. Our fair value assessment incorporates a variety of considerations, including (1) the short-term duration of the instruments, (2) our credit rating and (3) our historical incurrence of and expected future insignificant bad debt expense, which includes an evaluation of counterparty credit risk. The following table summarizes financial instruments, excluding receivables, payables and derivative financial instruments, and their reported fair values by individual balance sheet line item at June 30, 2020 and December 31, 2019. June 30, 2020 December 31, 2019 (In millions) Fair Value Carrying Amount Fair Value Carrying Amount Financial assets Current assets $ 4 $ 4 $ 4 $ 4 Other noncurrent assets 28 44 26 38 Total financial assets $ 32 $ 48 $ 30 $ 42 Financial liabilities Other current liabilities $ 61 $ 97 $ 62 $ 90 Long-term debt, including current portion (a) 5,558 5,530 6,174 5,529 Deferred credits and other liabilities 105 84 99 86 Total financial liabilities $ 5,724 $ 5,711 $ 6,335 $ 5,705 (a) Excludes debt issuance costs. Fair values of our financial assets included in other noncurrent assets, and of our financial liabilities included in other current liabilities and deferred credits and other liabilities, are measured using an income approach and most inputs are internally generated, which results in a Level 3 classification. Estimated future cash flows are discounted using a rate deemed appropriate to obtain the fair value.

Debt

Debt	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
Debt	Debt Revolving Credit Facility As of June 30, 2020, we had no borrowings against our $3.0 billion unsecured revolving credit facility (“Credit Facility”), as described below. The Credit Facility includes a covenant requiring our total debt to total capitalization ratio not to exceed 65% as of the last day of each fiscal quarter. In the event of a default, the lenders holding more than half of the commitments may terminate the commitments under the Credit Facility and require the immediate repayment of all outstanding borrowings and the cash collateralization of all outstanding letters of credit under the Credit Facility. As of June 30, 2020, we were in compliance with this covenant with a ratio of 33%. Long-term debt At June 30, 2020, we had $5.5 billion of total debt outstanding, with our next significant debt maturity in the amount of $1.0 billion due November 2022.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Stockholders' Equity	Stockholders’ EquityDuring the six months ended June 30, 2020, we acquired approximately 9 million common shares at a cost of $85 million, which were held as treasury stock. Including these repurchases, the total remaining share repurchase authorization was $1.3 billion at June 30, 2020. Purchases under the program are made at our discretion and may be in either open market transactions, including block purchases, or in privately negotiated transactions using cash on hand, cash generated from operations or proceeds from potential asset sales. This program may be changed based upon our financial condition or changes in market conditions and is subject to termination prior to completion.

Incentive Based Compensation

Incentive Based Compensation	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Incentive Based Compensation	Incentive Based Compensation Stock options, restricted stock awards and restricted stock units The following table presents a summary of activity for the first six months of 2020: Stock Options Restricted Stock Awards & Units Number of Shares Weighted Average Exercise Price Awards Weighted Average Grant Date Fair Value Outstanding at December 31, 2019 5,659,731 $ 23.55 7,174,386 $ 15.88 Granted 1,132,808 (a) $ 10.47 5,337,796 $ 8.55 Exercised/Vested (52,333) $ 7.22 (2,911,712) $ 15.93 Canceled (b) (565,219) $ 23.52 (1,405,754) $ 11.70 Outstanding at June 30, 2020 6,174,987 $ 21.29 8,194,716 $ 11.80 (a) The weighted average grant date fair value of stock option awards granted was $3.82 per share. (b) Included in canceled are forfeitures related to workforce reductions. Stock-based performance unit awards During the first six months of 2020, we granted 1,038,676 stock-based performance units to certain officers to be settled in shares. The grant date fair value per unit was $10.55, as calculated using a Monte Carlo valuation model. As of June 30, 2020 there were 1,658,088

Defined Benefit Postretirement

Defined Benefit Postretirement Plans	6 Months Ended
	Jun. 30, 2020
Retirement Benefits [Abstract]
Defined Benefit Postretirement Plans	Defined Benefit Postretirement Plans The following summarizes the components of net periodic benefit cost (credit): Three Months Ended June 30, Pension Benefits Other Benefits (In millions) 2020 2019 (d) 2020 2019 Service cost $ 5 $ 5 $ — $ — Interest cost 2 7 — 1 Expected return on plan assets (2) (8) — — Amortization: – prior service cost (credit) (2) (2) (5) (4) – actuarial loss 2 2 1 — Net settlement loss (a) 14 2 — — Net curtailment gain (b) (3) — (14) — Net periodic benefit cost (credit) (c) $ 16 $ 6 $ (18) $ (3) Six Months Ended June 30, Pension Benefits Other Benefits (In millions) 2020 2019 (d) 2020 2019 Service cost $ 10 $ 9 $ — $ — Interest cost 5 14 1 2 Expected return on plan assets (5) (16) — — Amortization: – prior service cost (credit) (4) (4) (9) (8) – actuarial loss 5 4 1 — Net settlement loss (a) 16 2 — — Net curtailment gain (b) (3) — (14) — Net periodic benefit cost (credit) (c) $ 24 $ 9 $ (21) $ (6) (a) Settlements are recognized as they occur, once it is probable that lump sum payments from a plan for a given year will exceed the plan’s total service and interest cost for that year. (b) Related to workforce reductions, which reduced the future expected years of service for employees participating in the plans. (c) Net periodic benefit cost (credit) reflects a calculated market-related value of plan assets which recognizes changes in fair value over three years. (d) Includes amounts related to the noncontributory defined benefit pension plan covering U.K. employees, prior to the plan being transferred to the buyer upon sale of the U.K. asset on July 1, 2019. During the first six months of 2020, we made contributions of $12 million to our funded pension plan and expect to contribute an additional $16 million this year. During the first six months of 2020, we made payments of $14 million and $8 million related to unfunded pension plans and other postretirement benefit plans.

Reclassifications Out of Accumu

Reclassifications Out of Accumulated Other Comprehensive Income (Loss)	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)	Reclassifications Out of Accumulated Other Comprehensive Income (Loss) The following table presents a summary of amounts reclassified from accumulated other comprehensive income (loss): Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Income Statement Line Postretirement and postemployment plans Amortization of prior service credit $ 7 $ 6 $ 13 $ 12 Other net periodic benefit credit Amortization of actuarial loss (3) (2) (6) (4) Other net periodic benefit credit Net settlement loss (14) (2) (16) (2) Other net periodic benefit credit Net curtailment gain 17 — 17 — Other net periodic benefit credit Total reclassifications to expense, net of tax (a) $ 7 $ 2 $ 8 $ 6 Net income

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	6 Months Ended
	Jun. 30, 2020
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information Six Months Ended June 30, (In millions) 2020 2019 Included in operating activities: Interest paid, net of amounts capitalized $ 126 $ 128 Income taxes paid to taxing authorities, net of refunds received (a) 4 66 Noncash investing activities: Increase (decrease) in asset retirement costs $ (6) $ 29 Asset retirement obligations assumed by buyer (b) — 109 (a) The six months ended June 30, 2020 and 2019 includes $4 million and $89 million, related to tax refunds. (b) In 2019, we closed on the sale of our working interest in the Droshky field (Gulf of Mexico), including our $98 million asset retirement obligation and the sale of our non-operated interest in the Atrush block in Kurdistan. Other noncash investing activities include accrued capital expenditures for the six months ended June 30, 2020 and 2019 of $48 million and $300 million.

Equity Method Investments

Equity Method Investments	6 Months Ended
	Jun. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments During the periods ended June 30, 2020 and December 31, 2019 our equity method investees were considered related parties and included: • EGHoldings, in which we have a 60% noncontrolling interest. EGHoldings is engaged in LNG production activity. • Alba Plant LLC, in which we have a 52% noncontrolling interest. Alba Plant LLC processes LPG. • AMPCO, in which we have a 45% noncontrolling interest. AMPCO is engaged in methanol production activity. Our equity method investments are summarized in the following table: (In millions) Ownership as of June 30, 2020 June 30, 2020 December 31, 2019 EGHoldings 60% $ 139 $ 310 Alba Plant LLC 52% 168 163 AMPCO 45% 169 190 Total $ 476 $ 663 In the second quarter of 2020, we recorded an impairment of $152 million to an investment in an equity method investee, which was reflected in income (loss) from equity method investments in our consolidated statements of income. See Note 11 to the consolidated financial statements for further information on the equity method investee impairment. Summarized financial information for equity method investees is as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Income data: Revenues and other income $ 111 $ 233 $ 283 $ 453 Income (loss) from operations (10) 82 (40) 131 Net income (loss) (13) 63 (39) 95 Revenues from related parties were $10 million and $20 million for the three and six months ended June 30, 2020 and $11 million and $21 million for the three and six months ended June 30, 2019 with the majority related to EGHoldings in all periods.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2020
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 contain clauses that require 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 and certain environmental liabilities resulting from the actions or inaction by Alba Plant LLC. Pursuant to these agreements, MEGPL agreed to indemnify third party property or events, including environmental liabilities, injury to Alba Plant LLC’s personnel, and damage to or loss of Alba Plant LLC’s automobiles. At this time, we cannot reasonably estimate this obligation as we do not have any history of prior indemnification claims, as completion of the plant modifications is not expected to finish until 2021, and as such, we do not have any history of 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 $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 either 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. We recorded a liability for these guarantees of $4 million as of June 30, 2020, with a corresponding receivable from our investees. Each of Equatorial Guinea LNG Operations, S.A. and Equatorial Guinea LNG Train 1, S.A. provided us with a pledge of its receivables as recourse against any payments we may make under the guaranty of Equatorial Guinea LNG Operations, S.A.’s performance. Various groups, including the State of North Dakota and three Indian tribes represented by the Bureau of Indian Affairs, have been involved in a dispute regarding the ownership of certain lands underlying the Missouri River and Little Missouri River. As a result, as of June 30, 2020, we have a $101 million current liability in suspended royalty and working interest revenue, including interest, and have a long-term receivable of $25 million for capital and expenses. In December 2019, we received a Notice of Violation from the North Dakota Department of Environmental Quality and a verbal notice of enforcement in January 2020 from the North Dakota Industrial Commission, related to a release of produced water in North Dakota. In January 2020, we received a Notice of Violation from the EPA related to the Clean Air Act. Each enforcement action will likely result in monetary sanctions in excess of $100,000; however, we do not believe these enforcement actions would have a material adverse effect on our consolidated financial position, results of operations or cash flow. 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. 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.

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2020
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 2019 Annual Report on Form 10-K. The results of operations for the second quarter and first six months of 2020 are not necessarily indicative of the results to be expected for the full year.

Income (Loss) and Dividends p_2

Income (Loss) and Dividends per Common Share (Tables)	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The per share calculations below exclude 7 million of stock options for each of the three and six months ended June 30, 2020 and 6 million of stock options for each of the three and six months ended June 30, 2019 that were antidilutive. Three Months Ended June 30, Six Months Ended June 30, (In millions, except per share data) 2020 2019 2020 2019 Net income (loss) $ (750) $ 161 $ (796) $ 335 Weighted average common shares outstanding 790 813 793 817 Effect of dilutive securities — 1 — — Weighted average common shares, diluted 790 814 793 817 Net income (loss) per share: Basic $ (0.95) $ 0.20 $ (1.00) $ 0.41 Diluted $ (0.95) $ 0.20 $ (1.00) $ 0.41 Dividends per share $ — $ 0.05 $ 0.05 $ 0.10

Revenues (Tables)

Revenues (Tables)	6 Months Ended
	Jun. 30, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables present our revenues from contracts with customers disaggregated by product type and geographic areas for the three and six months ended June 30 as follows: United States Three Months Ended June 30, 2020 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 142 $ 147 $ 32 $ 33 $ 7 $ 361 Natural gas liquids 16 3 13 4 1 37 Natural gas 20 5 24 4 1 54 Other 1 — — — 9 10 Revenues from contracts with customers $ 179 $ 155 $ 69 $ 41 $ 18 $ 462 Three Months Ended June 30, 2019 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 350 $ 453 $ 111 $ 77 $ 30 $ 1,021 Natural gas liquids 30 15 31 7 1 84 Natural gas 32 6 36 1 4 79 Other 1 — — — 15 16 Revenues from contracts with customers $ 413 $ 474 $ 178 $ 85 $ 50 $ 1,200 Six Months Ended June 30, 2020 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 449 $ 477 $ 116 $ 107 $ 40 $ 1,189 Natural gas liquids 31 13 34 7 3 88 Natural gas 44 13 53 7 4 121 Other 3 — — — 31 34 Revenues from contracts with customers $ 527 $ 503 $ 203 $ 121 $ 78 $ 1,432 Six Months Ended June 30, 2019 (In millions) Eagle Ford Bakken Oklahoma Northern Delaware Other U.S. Total Crude oil and condensate $ 668 $ 825 $ 188 $ 141 $ 58 $ 1,880 Natural gas liquids 65 25 53 15 3 161 Natural gas 66 18 81 7 10 182 Other 3 — — — 36 39 Revenues from contracts with customers $ 802 $ 868 $ 322 $ 163 $ 107 $ 2,262 International Three Months Ended June 30, 2020 (In millions) E.G. Crude oil and condensate $ 20 Natural gas liquids 1 Natural gas 7 Revenues from contracts with customers $ 28 Three Months Ended June 30, 2019 (In millions) E.G. U.K. Other Int’l Total Crude oil and condensate $ 101 $ 51 $ 9 $ 161 Natural gas liquids 1 — — 1 Natural gas 9 4 — 13 Other — 6 — 6 Revenues from contracts with customers $ 111 $ 61 $ 9 $ 181 Six Months Ended June 30, 2020 (In millions) E.G. Crude oil and condensate $ 65 Natural gas liquids 2 Natural gas 15 Revenues from contracts with customers $ 82 Six Months Ended June 30, 2019 (In millions) E.G. U.K. Other Int’l Total Crude oil and condensate $ 148 $ 107 $ 19 $ 274 Natural gas liquids 2 1 — 3 Natural gas 16 12 — 28 Other — 14 — 14 Revenues from contracts with customers $ 166 $ 134 $ 19 $ 319

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Three Months Ended June 30, 2020 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 462 $ 28 $ — $ 490 Net gain (loss) on commodity derivatives 26 — (96) (b) (70) Loss from equity method investments — — (152) (c) (152) Net loss on disposal of assets — — (2) (2) Other income 3 2 1 6 Less costs and expenses: Production 114 15 — 129 Shipping, handling and other operating 91 1 13 105 Exploration 26 — — 26 Depreciation, depletion and amortization 569 22 6 597 Taxes other than income 30 — — 30 General and administrative 32 3 53 (d) 88 Net interest and other — — 69 69 Other net periodic benefit credit — — (7) (e) (7) Income tax benefit (6) (5) (4) (15) Segment loss $ (365) $ (6) $ (379) $ (750) Total assets $ 16,791 $ 1,144 $ 632 $ 18,567 Capital expenditures (a) $ 137 $ — $ 2 $ 139 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 15 ). (c) Partial impairment of investment in equity method investee (See N ot e 2 3 ). (d) Includes severance expenses associated with workforce reductions of $13 million. (e) Includes pension settlement loss of $14 million and pension curtailment gain of $17 million (See N ote 2 0 ). Three Months Ended June 30, 2019 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 1,200 $ 181 $ — $ 1,381 Net gain on commodity derivatives 5 — 11 (b) 16 Income from equity method investments — 31 — 31 Net loss on disposal of assets — — (8) (c) (8) Other income 4 2 7 13 Less costs and expenses: Production 147 46 — 193 Shipping, handling and other operating 147 10 13 170 Exploration 26 — — 26 Depreciation, depletion and amortization 561 38 6 605 Impairments — — 18 (d) 18 Taxes other than income 79 — — 79 General and administrative 31 8 48 87 Net interest and other — — 64 64 Other net periodic benefit credit — (1) (1) (2) Income tax provision 3 17 12 32 Segment income (loss) $ 215 $ 96 $ (150) $ 161 Total assets $ 17,539 $ 2,913 $ 830 $ 21,282 Capital expenditures (a) $ 686 $ 10 $ 5 $ 701 (a) Includes accruals. (b) Unrealized gain on commodity derivative instruments (See Note 15 ). (c) Primarily related to the sale of certain non-core proved properties in our International segment (see No te 4 ). (d) Primarily as a result of the anticipated sale of non-core proved properties in our United States segment (See Note 11 ). Six Months Ended June 30, 2020 (In millions) U.S. Int’l Not Allocated to Segments Total Revenues from contracts with customers $ 1,432 $ 82 $ — $ 1,514 Net gain on commodity derivatives 57 — 75 (b) 132 Loss from equity method investments — (12) (152) (c) (164) Net gain on disposal of assets — — 7 7 Other income 7 4 2 13 Less costs and expenses: Production 257 32 — 289 Shipping, handling and other operating 231 4 14 249 Exploration 54 — — 54 Depreciation, depletion and amortization 1,186 43 12 1,241 Impairments — — 97 (d) 97 Taxes other than income 96 — — 96 General and administrative 64 7 93 (e) 164 Net interest and other — — 133 133 Other net periodic benefit credit — — (7) (f) (7) Income tax benefit (7) (5) (6) (18) Segment loss $ (385) $ (7) $ (404) $ (796) Total assets $ 16,791 $ 1,144 $ 632 $ 18,567 Capital expenditures (a) $ 698 $ — $ 9 $ 707 (a) Includes accruals. (b) Unrealized gain on commodity derivative instruments (See Note 15 ). (c) Partial impairment of investment in equity method investee (See N ote 23 ). (d) Includes the full impairment of the International reporting unit goodwill of $95 million (See N ote 14 ). (e) Includes severance expenses associated with workforce reductions of $13 million. (f) Includes pension settlement loss of $16 million and pension curtailment gain of $17 million (See Note 20 ). Six Months Ended June 30, 2019 (In millions) U.S. Int’l Not Allocated to Segments Total Revenue from contracts with customers $ 2,262 $ 319 $ — $ 2,581 Net gain (loss) on commodity derivatives 27 — (102) (b) (75) Income from equity method investments — 42 — 42 Net gain on disposal of assets — — 34 (c) 34 Other income 5 5 38 (d) 48 Less costs and expenses: Production 286 96 (2) 380 Shipping, handling and other operating 287 23 14 324 Exploration 85 — — 85 Depreciation, depletion and amortization 1,075 72 12 1,159 Impairments — — 24 (e) 24 Taxes other than income 153 — (2) 151 General and administrative 60 15 106 181 Net interest and other — — 113 113 Other net periodic benefit credit — (3) (4) (7) Income tax provision (benefit) 1 6 (122) (f) (115) Segment income (loss) $ 347 $ 157 $ (169) $ 335 Total assets $ 17,539 $ 2,913 $ 830 $ 21,282 Capital expenditures (a) $ 1,292 $ 15 $ 8 $ 1,315 (a) Includes accruals. (b) Unrealized loss on commodity derivative instruments (See Note 15 ). (c) Primarily related to the sale of our working interest in the Droshky field (Gulf of Mexico). (d) Primarily related to the indemnification of certain tax liabilities in connection with the 2010-2011 Federal Tax Audit (See Note 7 ). (e) Primarily as a result of anticipated sales of certain non-core proved properties in our International and United States segments. (f) Primarily relates to the settlement of the 2010-2011 Federal Tax Audit (See Note 7 ).

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Effective Income Tax Rate	For the three and six months ended June 30, 2020 and 2019, our effective income tax rates were as follows: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Effective income tax rate (a) 2 % 17 % 2 % (52) % (a) In all periods presented, we maintained our valuation allowance on our net federal deferred tax assets in the U.S.

Credit Losses (Tables)

Credit Losses (Tables)	6 Months Ended
	Jun. 30, 2020
Credit Loss [Abstract]
Changes in Allowance For Doubtful Account Balance	Changes in the allowance for doubtful accounts balance for the six months ended were as follows: (In millions) June 30, 2020 Beginning balance as of January 1 $ 11 Cumulative-effect adjustment 12 Current period provision (a) 6 Recoveries of amounts previously written off (6) Ending balance as of June 30 $ 23

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 30, 2020
Inventory Disclosure [Abstract]
Schedule of Inventory, Current	(In millions) June 30, 2020 December 31, 2019 Crude oil and natural gas $ 9 $ 10 Supplies and other items 68 62 Inventories $ 77 $ 72

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	6 Months Ended
	Jun. 30, 2020
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	(In millions) June 30, 2020 December 31, 2019 United States $ 15,899 $ 16,427 International 449 493 Corporate 76 80 Net property, plant and equipment $ 16,424 $ 17,000

Impairments (Tables)

Impairments (Tables)	6 Months Ended
	Jun. 30, 2020
Impairment Expense [Abstract]
Fair Value Measurements, Nonrecurring	The following table summarizes impairment charges of proved properties, goodwill and equity method investments and their corresponding fair values. Three Months Ended June 30, 2020 2019 (In millions) Fair Value Impairment Fair Value Impairment Long-lived assets held for use $ — $ — $ 19 $ 18 Equity method investment $ 142 $ 152 N/A $ — Six Months Ended June 30, 2020 2019 (In millions) Fair Value Impairment Fair Value Impairment Long-lived assets held for use $ — $ 2 $ 56 $ 24 Goodwill $ — $ 95 N/A $ — Equity method investment $ 142 $ 152 N/A $ —

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	6 Months Ended
	Jun. 30, 2020
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 for the six months ended June 30 were as follows: June 30, (In millions) 2020 2019 Beginning balance as of January 1 $ 255 $ 1,145 Incurred liabilities, including acquisitions 2 18 Settled liabilities, including dispositions (3) (129) Accretion expense (included in depreciation, depletion and amortization) 6 26 Revisions of estimates (8) 11 Held for sale — (864) Ending balance as of June 30 $ 252 $ 207

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2020
Leases [Abstract]
Supplemental Balance Sheet Information	Supplemental balance sheet information related to leases was as follows: (In millions) June 30, 2020 Operating Leases: Balance Sheet Location: Right-of-use asset Other noncurrent assets $ 153 Current portion of long-term lease liability Other current liabilities $ 83 Long-term lease liability Deferred credits and other liabilities $ 74
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 2020 $ 3 2021 6 2022 6 2023 6 2024 6 Thereafter 60 Total undiscounted cash flows $ 87

Goodwill (Tables)

Goodwill (Tables)	6 Months Ended
	Jun. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill Rollforward	June 30, (In millions) 2020 2019 Beginning balance as of January 1, gross $ 95 $ 97 Less: accumulated impairments — — Beginning balance, net 95 97 Dispositions — (2) Impairment (95) — Ending balance as of June 30, net $ — $ 95

Derivatives (Tables)

Derivatives (Tables)	6 Months Ended
	Jun. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in the Consolidated Balance Sheets	The following tables present the gross fair values of derivative instruments and the reported net amounts along with where they appear on the consolidated balance sheets. June 30, 2020 (In millions) Asset Liability Net Asset (Liability) Balance Sheet Location Not Designated as Hedges Commodity $ 100 $ 21 $ 79 Derivative assets Total Not Designated as Hedges $ 100 $ 21 $ 79 Cash Flow Hedges Interest Rate $ — $ 26 $ (26) Deferred credits and other liabilities Interest Rate 2 — 2 Other noncurrent assets Total Designated Hedges $ 2 $ 26 $ (24) Total $ 102 $ 47 $ 55 December 31, 2019 (In millions) Asset Liability Net Asset (Liability) Balance Sheet Location Not Designated as Hedges Commodity $ 9 $ 1 $ 8 Derivative assets Commodity 1 — 1 Other noncurrent assets Commodity — 5 (5) Other current liabilities Total Not Designated as Hedges $ 10 $ 6 $ 4 Cash Flow Hedges Interest Rate $ 2 $ — $ 2 Other noncurrent assets Total Designated Hedges $ 2 $ — $ 2 Total $ 12 $ 6 $ 6 The mark-to-market impact and settlement of our commodity derivative instruments appears in the table below and is reflected in net gain (loss) on commodity derivatives in the consolidated statements of income. Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Mark-to-market gain (loss) $ (96) $ 11 $ 75 $ (102) Net settlements of commodity derivative instruments $ 26 $ 5 $ 57 $ 27
Schedule of Notional Amounts of Outstanding Derivative Positions	The following table sets forth outstanding derivative contracts as of June 30, 2020, and the weighted average prices for those contracts: 2020 2021 Third Quarter Fourth Quarter Full Year Crude Oil NYMEX WTI Three-Way Collars Volume (Bbls/day) 80,000 80,000 — Weighted average price per Bbl: Ceiling $ 64.40 $ 64.40 $ — Floor $ 55.00 $ 55.00 $ — Sold put $ 48.00 $ 48.00 $ — NYMEX WTI Two-Way Collars Volume (Bbls/day) 33,478 — — Weighted average price per Bbl: Ceiling $ 40.47 $ — $ — Floor $ 30.98 $ — $ — Fixed Price WTI Swaps Volume (Bbls/day) 10,000 — — Weighted average price per Bbl $ 32.77 $ — $ — Basis Swaps - Argus WTI Midland (a) Volume (Bbls/day) 15,000 15,000 — Weighted average price per Bbl $ (0.94) $ (0.94) $ — Basis Swaps - NYMEX WTI / ICE Brent (b) Volume (Bbls/day) 5,000 5,000 808 Weighted average price per Bbl $ (7.24) $ (7.24) $ (7.24) NYMEX Roll Basis Swaps Volume (Bbls/day) 60,000 30,000 — Weighted average price per Bbl $ (1.58) $ (0.81) $ — Natural Gas Two-Way Collars Volume (MMBtu/day) — — 62,329 Weighted average price per MMBtu: Ceiling $ — $ — $ 3.07 Floor $ — $ — $ 2.44 Basis Swaps - WAHA / HH (c) Volume (MMBtu/day) 10,000 10,000 — Weighted average price per MMBtu $ (0.37) $ (0.37) $ — (a) The basis differential price is indexed against Argus WTI Midland. (b) The basis differential price is indexed against Intercontinental Exchange (“ICE”) Brent and NYMEX WTI. (c) The basis differential price is indexed against Waha and NYMEX Henry Hub. The following table sets forth outstanding derivative contracts entered into between July 1 and August 5, 2020, and the weighted average prices for those contracts: 2020 2021 Third Quarter Fourth Quarter Full Year Crude Oil NYMEX WTI Two-Way Collars Volume (Bbls/day) 3,261 10,000 10,000 Weighted average price per Bbl: Ceiling $ 48.00 $ 48.65 $ 52.37 Floor $ 36.50 $ 37.00 $ 35.00 Natural Gas Two-Way Collars Volume (MMBtu/day) 66,304 150,000 50,000 Weighted average price per MMBtu: Ceiling $ 2.49 $ 2.62 $ 2.93 Floor $ 2.00 $ 2.13 $ 2.40 NGL Fixed Price Ethane Swaps Volume (MMBtu/day) 7,304 10,000 — Weighted average price per Bbl $ 8.78 $ 8.78 $ —
Schedule of Interest Rate Swap Agreement	The following table presents, by maturity date, information about our interest rate swap agreements, including the weighted average LIBOR-based, fixed rate. June 30, 2020 December 31, 2019 Maturity Date Aggregate Notional Amount (in millions) Weighted Average, LIBOR Aggregate Notional Amount (in millions) Weighted Average, LIBOR November 1, 2022 $ 500 0.99 % $ — — % June 1, 2025 $ 300 0.96 % $ — — % September 9, 2026 $ 320 1.51 % $ 320 1.51 %

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following tables present assets and liabilities accounted for at fair value on a recurring basis as of June 30, 2020 and December 31, 2019 by hierarchy level. June 30, 2020 (In millions) Level 1 Level 2 Level 3 Total Derivative instruments, assets Commodity (a) $ — $ 88 $ — $ 88 Interest rate — 2 — 2 Derivative instruments, assets $ — $ 90 $ — $ 90 Derivative instruments, liabilities Commodity (a) $ (9) $ — $ — $ (9) Interest rate — (26) — (26) Derivative instruments, liabilities $ (9) $ (26) $ — $ (35) Total $ (9) $ 64 $ — $ 55 December 31, 2019 (In millions) Level 1 Level 2 Level 3 Total Derivative instruments, assets Commodity (a) $ — $ 7 $ — $ 7 Interest rate — 2 — 2 Derivative instruments, assets $ — $ 9 $ — $ 9 Derivative instruments, liabilities Commodity (a) $ (3) $ — $ — $ (3) Derivative instruments, liabilities $ (3) $ — $ — $ (3) Total $ (3) $ 9 $ — $ 6 (a) Derivative instruments are recorded on a net basis in our consolidated balance sheet. See Note 15
Fair Value, by Balance Sheet Grouping	The following table summarizes financial instruments, excluding receivables, payables and derivative financial instruments, and their reported fair values by individual balance sheet line item at June 30, 2020 and December 31, 2019. June 30, 2020 December 31, 2019 (In millions) Fair Value Carrying Amount Fair Value Carrying Amount Financial assets Current assets $ 4 $ 4 $ 4 $ 4 Other noncurrent assets 28 44 26 38 Total financial assets $ 32 $ 48 $ 30 $ 42 Financial liabilities Other current liabilities $ 61 $ 97 $ 62 $ 90 Long-term debt, including current portion (a) 5,558 5,530 6,174 5,529 Deferred credits and other liabilities 105 84 99 86 Total financial liabilities $ 5,724 $ 5,711 $ 6,335 $ 5,705

Incentive Based Compensation (T

Incentive Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Schedule of Stock Options, Restricted Stock Awards and Restricted Stock Units Activity	The following table presents a summary of activity for the first six months of 2020: Stock Options Restricted Stock Awards & Units Number of Shares Weighted Average Exercise Price Awards Weighted Average Grant Date Fair Value Outstanding at December 31, 2019 5,659,731 $ 23.55 7,174,386 $ 15.88 Granted 1,132,808 (a) $ 10.47 5,337,796 $ 8.55 Exercised/Vested (52,333) $ 7.22 (2,911,712) $ 15.93 Canceled (b) (565,219) $ 23.52 (1,405,754) $ 11.70 Outstanding at June 30, 2020 6,174,987 $ 21.29 8,194,716 $ 11.80 (a) The weighted average grant date fair value of stock option awards granted was $3.82 per share. (b) Included in canceled are forfeitures related to workforce reductions.

Defined Benefit Postretiremen_2

Defined Benefit Postretirement Plans (Tables)	6 Months Ended
	Jun. 30, 2020
Retirement Benefits [Abstract]
Schedule of Net Periodic Benefit Cost	The following summarizes the components of net periodic benefit cost (credit): Three Months Ended June 30, Pension Benefits Other Benefits (In millions) 2020 2019 (d) 2020 2019 Service cost $ 5 $ 5 $ — $ — Interest cost 2 7 — 1 Expected return on plan assets (2) (8) — — Amortization: – prior service cost (credit) (2) (2) (5) (4) – actuarial loss 2 2 1 — Net settlement loss (a) 14 2 — — Net curtailment gain (b) (3) — (14) — Net periodic benefit cost (credit) (c) $ 16 $ 6 $ (18) $ (3) Six Months Ended June 30, Pension Benefits Other Benefits (In millions) 2020 2019 (d) 2020 2019 Service cost $ 10 $ 9 $ — $ — Interest cost 5 14 1 2 Expected return on plan assets (5) (16) — — Amortization: – prior service cost (credit) (4) (4) (9) (8) – actuarial loss 5 4 1 — Net settlement loss (a) 16 2 — — Net curtailment gain (b) (3) — (14) — Net periodic benefit cost (credit) (c) $ 24 $ 9 $ (21) $ (6) (a) Settlements are recognized as they occur, once it is probable that lump sum payments from a plan for a given year will exceed the plan’s total service and interest cost for that year. (b) Related to workforce reductions, which reduced the future expected years of service for employees participating in the plans. (c) Net periodic benefit cost (credit) reflects a calculated market-related value of plan assets which recognizes changes in fair value over three years. (d) Includes amounts related to the noncontributory defined benefit pension plan covering U.K. employees, prior to the plan being transferred to the buyer upon sale of the U.K. asset on July 1, 2019.

Reclassifications Out of Accu_2

Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Schedule of Amounts Reclassified out of Accumulated Other Comprehensive Income (Loss)	The following table presents a summary of amounts reclassified from accumulated other comprehensive income (loss): Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Income Statement Line Postretirement and postemployment plans Amortization of prior service credit $ 7 $ 6 $ 13 $ 12 Other net periodic benefit credit Amortization of actuarial loss (3) (2) (6) (4) Other net periodic benefit credit Net settlement loss (14) (2) (16) (2) Other net periodic benefit credit Net curtailment gain 17 — 17 — Other net periodic benefit credit Total reclassifications to expense, net of tax (a) $ 7 $ 2 $ 8 $ 6 Net income

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	6 Months Ended
	Jun. 30, 2020
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Six Months Ended June 30, (In millions) 2020 2019 Included in operating activities: Interest paid, net of amounts capitalized $ 126 $ 128 Income taxes paid to taxing authorities, net of refunds received (a) 4 66 Noncash investing activities: Increase (decrease) in asset retirement costs $ (6) $ 29 Asset retirement obligations assumed by buyer (b) — 109 (a) The six months ended June 30, 2020 and 2019 includes $4 million and $89 million, related to tax refunds. (b) In 2019, we closed on the sale of our working interest in the Droshky field (Gulf of Mexico), including our $98 million asset retirement obligation and the

Equity Method Investments (Tabl

Equity Method Investments (Tables)	6 Months Ended
	Jun. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Equity Method Investments	Our equity method investments are summarized in the following table: (In millions) Ownership as of June 30, 2020 June 30, 2020 December 31, 2019 EGHoldings 60% $ 139 $ 310 Alba Plant LLC 52% 168 163 AMPCO 45% 169 190 Total $ 476 $ 663 In the second quarter of 2020, we recorded an impairment of $152 million to an investment in an equity method investee, which was reflected in income (loss) from equity method investments in our consolidated statements of income. See Note 11 to the consolidated financial statements for further information on the equity method investee impairment. Summarized financial information for equity method investees is as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Income data: Revenues and other income $ 111 $ 233 $ 283 $ 453 Income (loss) from operations (10) 82 (40) 131 Net income (loss) (13) 63 (39) 95

Accounting Standards (Details)

Accounting Standards (Details) - USD ($) $ in Millions	Jan. 01, 2020	Mar. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment	$ (12)	$ (31)
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment	$ (12)	$ (31)

Income (Loss) and Dividends p_3

Income (Loss) and Dividends per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)	7		6		7	6
Net income	$ (750)	$ (46)	$ 161	$ 174	$ (796)	$ 335
Weighted average common shares outstanding (in shares)	790		813		793	817
Effect of dilutive securities (in shares)	0		1		0	0
Weighted average common shares, diluted (in shares)	790		814		793	817
Net income (loss) per share:
Basic (in dollars per share)	$ (0.95)		$ 0.20		$ (1)	$ 0.41
Per diluted share:
Diluted (in dollars per share)	(0.95)		0.20		(1)	0.41
Dividends per share (in dollars per share)	$ 0	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.10

Dispositions - International Se

Dispositions - International Segment (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property and equipment				$ 9	$ 69
Income before income taxes		$ (765)	$ 193	$ (814)	220
International E&P | U.K. Business | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property and equipment	$ 95
Income before income taxes			18		$ 28
International E&P | Atrush Block in Kurdistan | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property and equipment			$ 63
Percentage of oil and gas property disposed			15.00%

Revenues - Narrative (Details)

Revenues - Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Receivables from contract with customer	$ 487	$ 837

Revenues - Revenues from Contra

Revenues - Revenues from Contracts with Customers by Product Type and Geographic Areas (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 490	$ 1,381	$ 1,514	$ 2,581
United States E&P
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	462	1,200	1,432	2,262
United States E&P | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	179	413	527	802
United States E&P | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	155	474	503	868
United States E&P | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	69	178	203	322
United States E&P | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	41	85	121	163
United States E&P | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	18	50	78	107
United States E&P | Crude oil and condensate
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	361	1,021	1,189	1,880
United States E&P | Crude oil and condensate | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	142	350	449	668
United States E&P | Crude oil and condensate | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	147	453	477	825
United States E&P | Crude oil and condensate | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	32	111	116	188
United States E&P | Crude oil and condensate | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	33	77	107	141
United States E&P | Crude oil and condensate | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	7	30	40	58
United States E&P | Natural gas liquids
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	37	84	88	161
United States E&P | Natural gas liquids | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	16	30	31	65
United States E&P | Natural gas liquids | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	3	15	13	25
United States E&P | Natural gas liquids | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	13	31	34	53
United States E&P | Natural gas liquids | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	4	7	7	15
United States E&P | Natural gas liquids | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1	1	3	3
United States E&P | Natural gas
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	54	79	121	182
United States E&P | Natural gas | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	20	32	44	66
United States E&P | Natural gas | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	5	6	13	18
United States E&P | Natural gas | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	24	36	53	81
United States E&P | Natural gas | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	4	1	7	7
United States E&P | Natural gas | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1	4	4	10
United States E&P | Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	10	16	34	39
United States E&P | Other | Eagle Ford
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1	1	3	3
United States E&P | Other | Bakken
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
United States E&P | Other | Oklahoma
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
United States E&P | Other | Northern Delaware
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
United States E&P | Other | Other U.S.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	9	15	31	36
International E&P
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		181		319
International E&P | E.G.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	28	111	82	166
International E&P | U.K.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		61		134
International E&P | Other Int’l
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		9		19
International E&P | Crude oil and condensate
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		161		274
International E&P | Crude oil and condensate | E.G.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	20	101	65	148
International E&P | Crude oil and condensate | U.K.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		51		107
International E&P | Crude oil and condensate | Other Int’l
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		9		19
International E&P | Natural gas liquids
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		1		3
International E&P | Natural gas liquids | E.G.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1	1	2	2
International E&P | Natural gas liquids | U.K.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		0		1
International E&P | Natural gas liquids | Other Int’l
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		0		0
International E&P | Natural gas
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		13		28
International E&P | Natural gas | E.G.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 7	9	$ 15	16
International E&P | Natural gas | U.K.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		4		12
International E&P | Natural gas | Other Int’l
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		0		0
International E&P | Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		6		14
International E&P | Other | E.G.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		0		0
International E&P | Other | U.K.
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		6		14
International E&P | Other | Other Int’l
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		$ 0		$ 0

Segment Information (Details)

Segment Information (Details) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Jun. 30, 2020USD ($)segment	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment					2
Revenues from contracts with customers	$ 490		$ 1,381		$ 1,514	$ 2,581
Net gain (loss) on commodity derivatives	(70)		16		132	(75)
Income (loss) from equity method investments	(152)		31		(164)	42
Net gain (loss) on disposal of assets	(2)		(8)		7	34
Other income	6		13		13	48
Less costs and expenses:
Production	129		193		289	380
Shipping, handling and other operating	105		170		249	324
Exploration	26		26		54	85
Depreciation, depletion and amortization	597		605		1,241	1,159
Impairments	0		18		97	24
Taxes other than income	30		79		96	151
General and administrative	88		87		164	181
Net interest and other	69		64		133	113
Other net periodic benefit credit	(7)		(2)		(7)	(7)
Income tax provision (benefit)	(15)		32		(18)	(115)
Net income	(750)	$ (46)	161	$ 174	(796)	335
Assets	18,567		21,282		18,567	21,282	$ 20,245
Capital expenditures	139		701		707	1,315
Severance costs					13
Goodwill impairment loss					95	0
Pension Plan
Less costs and expenses:
Other net periodic benefit credit	14		2		16	2
Net curtailment gain	3		0		3	0
Not Allocated to Segments
Segment Reporting Information [Line Items]
Revenues from contracts with customers	0		0		0	0
Net gain (loss) on commodity derivatives	(96)		11		75	(102)
Income (loss) from equity method investments	(152)		0		(152)	0
Net gain (loss) on disposal of assets	(2)		(8)		7	34
Other income	1		7		2	38
Less costs and expenses:
Production	0		0		0	(2)
Shipping, handling and other operating	13		13		14	14
Exploration	0		0		0	0
Depreciation, depletion and amortization	6		6		12	12
Impairments			18		97	24
Taxes other than income	0		0		0	(2)
General and administrative	53		48		93	106
Net interest and other	69		64		133	113
Other net periodic benefit credit	(7)		(1)		(7)	(4)
Income tax provision (benefit)	(4)		12		(6)	(122)
Net income	(379)		(150)		(404)	(169)
Assets	632		830		632	830
Capital expenditures	2		5		9	8
Severance costs	13
Not Allocated to Segments | Pension Plan
Less costs and expenses:
Net curtailment gain	17				17
United States E&P
Segment Reporting Information [Line Items]
Revenues from contracts with customers	462		1,200		1,432	2,262
United States E&P | Operating Segments
Segment Reporting Information [Line Items]
Revenues from contracts with customers	462		1,200		1,432	2,262
Net gain (loss) on commodity derivatives	26		5		57	27
Income (loss) from equity method investments	0		0		0	0
Net gain (loss) on disposal of assets	0		0		0	0
Other income	3		4		7	5
Less costs and expenses:
Production	114		147		257	286
Shipping, handling and other operating	91		147		231	287
Exploration	26		26		54	85
Depreciation, depletion and amortization	569		561		1,186	1,075
Impairments			0		0	0
Taxes other than income	30		79		96	153
General and administrative	32		31		64	60
Net interest and other	0		0		0	0
Other net periodic benefit credit	0		0		0	0
Income tax provision (benefit)	(6)		3		(7)	1
Net income	(365)		215		(385)	347
Assets	16,791		17,539		16,791	17,539
Capital expenditures	137		686		698	1,292
Int'l E&P
Segment Reporting Information [Line Items]
Revenues from contracts with customers			181			319
Int'l E&P | Operating Segments
Segment Reporting Information [Line Items]
Revenues from contracts with customers	28		181		82	319
Net gain (loss) on commodity derivatives	0		0		0	0
Income (loss) from equity method investments	0		31		(12)	42
Net gain (loss) on disposal of assets	0		0		0	0
Other income	2		2		4	5
Less costs and expenses:
Production	15		46		32	96
Shipping, handling and other operating	1		10		4	23
Exploration	0		0		0	0
Depreciation, depletion and amortization	22		38		43	72
Impairments			0		0	0
Taxes other than income	0		0		0	0
General and administrative	3		8		7	15
Net interest and other	0		0		0	0
Other net periodic benefit credit	0		(1)		0	(3)
Income tax provision (benefit)	(5)		17		(5)	6
Net income	(6)		96		(7)	157
Assets	1,144		2,913		1,144	2,913
Capital expenditures	$ 0		$ 10		$ 0	$ 15

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended			6 Months Ended
	Aug. 06, 2020	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Valuation Allowance [Line Items]
Effective income tax expense (benefit) rate		2.00%	17.00%		2.00%	(52.00%)
Tax benefit from settlement				$ 126
Tax benefit from internal restructuring				$ 18
Effective income tax expense (benefit) rate, excluding discrete items						13.00%
Proceeds from income tax refunds					$ 4	$ 89
Subsequent Event
Valuation Allowance [Line Items]
Proceeds from income tax refunds	$ 89

Credit Losses (Details)

Credit Losses (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Beginning balance as of January 1	$ 11
Current period provision	6
Recoveries of amounts previously written off	(6)
Ending balance as of June 30	23
Cumulative-effect adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Beginning balance as of January 1	12
JIB Receivables
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Current period provision	7
Trade Receivables
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Current period provision	$ (1)

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Crude oil and natural gas	$ 9	$ 10
Supplies and other items	68	62
Inventories	$ 77	$ 72

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 16,424,000,000	$ 17,000,000,000
Exploratory well costs capitalized greater than one year after completion of drilling	0	0
Operating Segments | United States E&P
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	15,899,000,000	16,427,000,000
Operating Segments | International E&P
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	449,000,000	493,000,000
Not Allocated to Segments
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 76,000,000	$ 80,000,000

Impairments - Fair Value Measur

Impairments - Fair Value Measurements, Nonrecurring (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairments			$ 97	$ 24
Goodwill	$ 0	$ 95	0	95	$ 95	$ 97
Goodwill impairment loss			95	0
Equity method investments	476		476		$ 663
Oil and Gas Properties
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long lived assets held for use, fair value	0	19	0	56
Impairments	0	18	2	24
Goodwill
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill	0		0
Goodwill impairment loss			95	0
Equity Method Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments	142		$ 142
Equity method investment, impairment	$ 152	$ 0		$ 0

Impairments - Narrative (Detail

Impairments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investment, difference between carrying amount and underlying equity	$ 126	$ 126
Equity method investment, difference between carrying amount and underlying equity, amortization period	6 years 6 months
Goodwill impairment loss		95	$ 0
Impairments		$ 97	$ 24

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligation, beginning balance	$ 255	$ 1,145
Incurred liabilities, including acquisitions	2	18
Settled liabilities, including dispositions	(3)	(129)
Accretion expense (included in depreciation, depletion and amortization)	6	26
Revisions of estimates	(8)	11
Held for sale	0	(864)
Asset retirement obligation, ending balance	252	207
Asset retirement obligation, current	$ 10	18
UNITED KINGDOM | Disposal Group, Held-for-sale, Not Discontinued Operations
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Held for sale		$ (966)

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information (Details) $ in Millions	Jun. 30, 2020USD ($)
Leases [Abstract]
Right-of-use asset	$ 153
Current portion of long-term lease liability	83
Long-term lease liability	$ 74
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsNoncurrent
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	mro:Deferredcreditandotherliabilities

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)
Leases [Abstract]
Annual payments to be received	$ 6
Maximum financing available	380
Total costs incurred under lease	$ 87
Term of contract	5 years
Finance lease extension term	5 years
Residual value guarantee	89.00%
Maximum financing available, reduced amount requested	$ 340

Leases - Lease Payments to be R

Leases - Lease Payments to be Received (Details) $ in Millions	Jun. 30, 2020USD ($)
Leases [Abstract]
2020	$ 3
2021	6
2022	6
2023	6
2024	6
Thereafter	60
Total undiscounted cash flows	$ 87

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 0	$ 95	$ 95	$ 97
Goodwill impairment loss	$ 95	$ 0

Goodwill - Rollforward (Details

Goodwill - Rollforward (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Beginning balance as of January 1, gross			$ 95	$ 97
Less: accumulated impairments			$ 0	$ 0
Beginning balance, net	$ 95	$ 97
Dispositions	0	(2)
Impairment	(95)	0
Ending balance as of June 30, net	$ 0	$ 95

Derivatives - Schedule of Deriv

Derivatives - Schedule of Derivative Instruments in the Consolidated Balance Sheets (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Asset	$ 102	$ 12
Liability	47	6
Net Asset (Liability)	55	6
Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	100	10
Liability	21	6
Net Asset (Liability)	79	4
Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Asset	2	2
Liability	26	0
Net Asset (Liability)	(24)	2
Commodity | Derivative assets | Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	100	9
Liability	21	1
Net Asset (Liability)	79	8
Commodity | Other current liabilities | Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset		0
Liability		5
Net Asset (Liability)		(5)
Commodity | Other noncurrent assets | Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset		1
Liability		0
Net Asset (Liability)		1
Interest Rate | Deferred credits and other liabilities | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Asset	0
Liability	26
Net Asset (Liability)	(26)
Interest Rate | Other noncurrent assets | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Asset	2	2
Liability	0	0
Net Asset (Liability)	$ 2	$ 2

Derivatives - Outstanding Deriv

Derivatives - Outstanding Derivative Contracts (Details) - Not Designated as Hedges	Jun. 30, 2020Bbls_per_dayMMBTU_per_day$ / MMBTU$ / bbl
Three-Way Collars - Crude Oil 2020 Q3
Derivative [Line Items]
Derivative, volume | Bbls_per_day	80,000
Derivative, ceiling	64.40
Derivative, floor	55
Derivative, sold put	48
Three-Way Collars - Crude Oil 2020 Q4
Derivative [Line Items]
Derivative, volume | Bbls_per_day	80,000
Derivative, ceiling	64.40
Derivative, floor	55
Derivative, sold put	48
Three-Way Collars - Crude Oil 2021
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Derivative, ceiling	0
Derivative, floor	0
Derivative, sold put	0
Two-Way Collars - Crude Oil 2020 Q3
Derivative [Line Items]
Derivative, volume | Bbls_per_day	33,478
Derivative, ceiling	40.47
Derivative, floor	30.98
Two-Way Collars - Crude Oil 2020 Q4
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Derivative, ceiling	0
Derivative, floor	0
Two-Way Collars - Crude Oil 2021
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Derivative, ceiling	0
Derivative, floor	0
Fixed Rate Swaps - Crude Oil 2020 Q3
Derivative [Line Items]
Derivative, volume | Bbls_per_day	10,000
Fixed Rate Swaps - Crude Oil 2020 Q3 | Short
Derivative [Line Items]
Derivative, weighted average price	32.77
Fixed Rate Swaps - Crude Oil 2020 Q4
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Rate Swaps - Crude Oil 2020 Q4 | Short
Derivative [Line Items]
Derivative, weighted average price	0
Fixed Rate Swaps - Crude Oil 2021
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Rate Swaps - Crude Oil 2021 | Short
Derivative [Line Items]
Derivative, weighted average price	0
Midland Basis Swaps - Crude Oil 2020 Q3
Derivative [Line Items]
Derivative, volume | Bbls_per_day	15,000
Midland Basis Swaps - Crude Oil 2020 Q3 | Long
Derivative [Line Items]
Derivative, weighted average price	0.94
Midland Basis Swaps - Crude Oil 2020 Q4
Derivative [Line Items]
Derivative, volume | Bbls_per_day	15,000
Midland Basis Swaps - Crude Oil 2020 Q4 | Long
Derivative [Line Items]
Derivative, weighted average price	0.94
Midland Basis Swaps - Crude Oil 2021
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Midland Basis Swaps - Crude Oil 2021 | Long
Derivative [Line Items]
Derivative, weighted average price	0
Brent Basis Swaps - Crude Oil 2020 Q3
Derivative [Line Items]
Derivative, volume | Bbls_per_day	5,000
Brent Basis Swaps - Crude Oil 2020 Q3 | Long
Derivative [Line Items]
Derivative, weighted average price	7.24
Brent Basis Swaps - Crude Oil 2020 Q4
Derivative [Line Items]
Derivative, volume | Bbls_per_day	5,000
Brent Basis Swaps - Crude Oil 2020 Q4 | Long
Derivative [Line Items]
Derivative, weighted average price	7.24
Brent Basis Swaps - Crude Oil 2021
Derivative [Line Items]
Derivative, volume | Bbls_per_day	808
Brent Basis Swaps - Crude Oil 2021 | Long
Derivative [Line Items]
Derivative, weighted average price	7.24
NYMEX Roll Basis Swaps - Crude Oil 2020 Q3
Derivative [Line Items]
Derivative, volume | Bbls_per_day	60,000
NYMEX Roll Basis Swaps - Crude Oil 2020 Q3 | Long
Derivative [Line Items]
Derivative, weighted average price	1.58
NYMEX Roll Basis Swaps - Crude Oil 2020 Q4
Derivative [Line Items]
Derivative, volume | Bbls_per_day	30,000
NYMEX Roll Basis Swaps - Crude Oil 2020 Q4 | Long
Derivative [Line Items]
Derivative, weighted average price	0.81
NYMEX Roll Basis Swaps - Crude Oil 2021
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
NYMEX Roll Basis Swaps - Crude Oil 2021 | Long
Derivative [Line Items]
Derivative, weighted average price	0
Two-Way Collars - Natural Gas 2020 Q3
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Derivative, ceiling | $ / MMBTU	0
Derivative, floor | $ / MMBTU	0
Two-Way Collars - Natural Gas 2020 Q4
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
Derivative, ceiling | $ / MMBTU	0
Derivative, floor | $ / MMBTU	0
Two-Way Collars - Natural Gas 2021
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	62,329
Derivative, ceiling | $ / MMBTU	3.07
Derivative, floor | $ / MMBTU	2.44
WAHA/HH Basis Swaps - Natural Gas 2020 Q3
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	10,000
WAHA/HH Basis Swaps - Natural Gas 2020 Q3 | Long
Derivative [Line Items]
Derivative, weighted average price | $ / MMBTU	0.37
WAHA/HH Basis Swaps - Natural Gas 2020 Q4
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	10,000
WAHA/HH Basis Swaps - Natural Gas 2020 Q4 | Long
Derivative [Line Items]
Derivative, weighted average price | $ / MMBTU	0.37
WAHA/HH Basis Swaps - Natural Gas 2021
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	0
WAHA/HH Basis Swaps - Natural Gas 2021 | Long
Derivative [Line Items]
Derivative, weighted average price | $ / MMBTU	0

Derivatives - Subsequent Event

Derivatives - Subsequent Event Derivative Contracts (Details) - Not Designated as Hedges	Aug. 05, 2020Bbls_per_dayMMBTU_per_day$ / bbl$ / MMBTU	Jun. 30, 2020MMBTU_per_dayBbls_per_day$ / bbl$ / MMBTU
Two-Way Collars - Crude Oil 2020 Q3
Derivative [Line Items]
Derivative, volume | Bbls_per_day		33,478
Derivative, ceiling		40.47
Derivative, floor		30.98
Two-Way Collars - Crude Oil 2020 Q3 | Subsequent Event
Derivative [Line Items]
Derivative, volume | Bbls_per_day	3,261
Derivative, ceiling	48
Derivative, floor	36.50
Two-Way Collars - Crude Oil 2020 Q4
Derivative [Line Items]
Derivative, volume | Bbls_per_day		0
Derivative, ceiling		0
Derivative, floor		0
Two-Way Collars - Crude Oil 2020 Q4 | Subsequent Event
Derivative [Line Items]
Derivative, volume | Bbls_per_day	10,000
Derivative, ceiling	48.65
Derivative, floor	37
Two-Way Collars - Crude Oil 2021
Derivative [Line Items]
Derivative, volume | Bbls_per_day		0
Derivative, ceiling		0
Derivative, floor		0
Two-Way Collars - Crude Oil 2021 | Subsequent Event
Derivative [Line Items]
Derivative, volume | Bbls_per_day	10,000
Derivative, ceiling	52.37
Derivative, floor	35
Two-Way Collars - Natural Gas 2020 Q3
Derivative [Line Items]
Derivative, volume | MMBTU_per_day		0
Derivative, ceiling | $ / MMBTU		0
Derivative, floor | $ / MMBTU		0
Two-Way Collars - Natural Gas 2020 Q3 | Subsequent Event
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	66,304
Derivative, ceiling | $ / MMBTU	2.49
Derivative, floor | $ / MMBTU	2
Two-Way Collars - Natural Gas 2020 Q4
Derivative [Line Items]
Derivative, volume | MMBTU_per_day		0
Derivative, ceiling | $ / MMBTU		0
Derivative, floor | $ / MMBTU		0
Two-Way Collars - Natural Gas 2020 Q4 | Subsequent Event
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	150,000
Derivative, ceiling | $ / MMBTU	2.62
Derivative, floor | $ / MMBTU	2.13
Two-Way Collars - Natural Gas 2021
Derivative [Line Items]
Derivative, volume | MMBTU_per_day		62,329
Derivative, ceiling | $ / MMBTU		3.07
Derivative, floor | $ / MMBTU		2.44
Two-Way Collars - Natural Gas 2021 | Subsequent Event
Derivative [Line Items]
Derivative, volume | MMBTU_per_day	50,000
Derivative, ceiling | $ / MMBTU	2.93
Derivative, floor | $ / MMBTU	2.40
Fixed Price Ethane Swaps - NGL 2020 Q3 | Subsequent Event
Derivative [Line Items]
Derivative, volume | Bbls_per_day	7,304
Fixed Price Ethane Swaps - NGL 2020 Q3 | Subsequent Event | Short
Derivative [Line Items]
Derivative, weighted average price	8.78
Fixed Price Ethane Swaps - NGL 2020 Q4 | Subsequent Event
Derivative [Line Items]
Derivative, volume | Bbls_per_day	10,000
Fixed Price Ethane Swaps - NGL 2020 Q4 | Subsequent Event | Short
Derivative [Line Items]
Derivative, weighted average price	8.78
Fixed Price Ethane Swaps - NGL 2021 | Subsequent Event
Derivative [Line Items]
Derivative, volume | Bbls_per_day	0
Fixed Price Ethane Swaps - NGL 2021 | Subsequent Event | Short
Derivative [Line Items]
Derivative, weighted average price	0

Derivatives - Narrative (Detail

Derivatives - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Aug. 06, 2020	Dec. 31, 2019
Interest Rate
Derivative Instruments, Gain (Loss) [Line Items]
Deferred loss related to interest rate swaps	$ 24
Interest Rate Contract, Maturing November 1, 2022 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 500
Weighted average interest rate, LIBOR	0.99%
Cash Flow Hedges | Interest Rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount			$ 320
Notes Due 2022 | Cash Flow Hedges | Interest Rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 500
Notes Due 2025 | Cash Flow Hedges | Interest Rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 300
Notes Due 2025 | Subsequent Event | Cash Flow Hedges | Interest Rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount		$ 50
Weighted average interest rate, LIBOR		0.90%

Derivatives - Schedule of mark-

Derivatives - Schedule of mark-to-market impact and commodity derivative settlements (Details) - Commodity - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Mark-to-market gain (loss)	$ (96)	$ 11	$ 75	$ (102)
Net settlements of commodity derivative instruments	$ 26	$ 5	$ 57	$ 27

Derivatives - Schedule of Inter

Derivatives - Schedule of Interest Rate Swap Agreements (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Interest Rate Contract, Maturing November 1, 2022 [Member]
Derivative [Line Items]
Derivative, notional amount	$ 500
Weighted average interest rate, LIBOR	0.99%
Interest Rate Contract, Maturing June 1, 2025 [Member]
Derivative [Line Items]
Derivative, notional amount	$ 300
Weighted average interest rate, LIBOR	0.96%
Interest Rate Contract, Maturing September 9, 2026 [Member]
Derivative [Line Items]
Derivative, notional amount	$ 320	$ 320
Weighted average interest rate, LIBOR	1.51%	1.51%

Fair Value Measurements - Fair

Fair Value Measurements - Fair Values - Recurring (Details) - Recurring - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	$ 90	$ 9
Derivative instruments, liabilities	(35)	(3)
Total	55	6
Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	88	7
Derivative instruments, liabilities	(9)	(3)
Interest Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	2	2
Derivative instruments, liabilities	(26)
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	0	0
Derivative instruments, liabilities	(9)	(3)
Total	(9)	(3)
Level 1 | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	0	0
Derivative instruments, liabilities	(9)	(3)
Level 1 | Interest Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	0	0
Derivative instruments, liabilities	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	90	9
Derivative instruments, liabilities	(26)	0
Total	64	9
Level 2 | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	88	7
Derivative instruments, liabilities	0	0
Level 2 | Interest Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	2	2
Derivative instruments, liabilities	(26)
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 | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	0	0
Derivative instruments, liabilities	0	0
Level 3 | Interest Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, assets	0	$ 0
Derivative instruments, liabilities	$ 0

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair Values - Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Fair Value
Financial assets
Current assets	$ 4	$ 4
Other noncurrent assets	28	26
Total financial assets	32	30
Financial liabilities
Other current liabilities	61	62
Long-term debt, including current portion	5,558	6,174
Deferred credits and other liabilities	105	99
Total financial liabilities	5,724	6,335
Carrying Amount
Financial assets
Current assets	4	4
Other noncurrent assets	44	38
Total financial assets	48	42
Financial liabilities
Other current liabilities	97	90
Long-term debt, including current portion	5,530	5,529
Deferred credits and other liabilities	84	86
Total financial liabilities	$ 5,711	$ 5,705

Debt - Revolving Credit Facilit

Debt - Revolving Credit Facility (Details) - Revolving Credit Facility	Jun. 30, 2020USD ($)
Line of Credit Facility [Line Items]
Line of credit, outstanding amount	$ 0
Maximum borrowing capacity	$ 3,000,000,000
Covenant, ratio of indebtedness to net capital, maximum	0.65
Ratio of indebtedness to net capital	0.33

Debt - Long-Term Debt (Details)

Debt - Long-Term Debt (Details) $ in Billions	Jun. 30, 2020USD ($)
Debt Instrument [Line Items]
Outstanding debt	$ 5.5
Senior Unsecured Note Due 2022
Debt Instrument [Line Items]
Outstanding debt	$ 1

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020
Equity, Class of Treasury Stock [Line Items]
Shares repurchased	$ 91	$ 236	$ 30
Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Shares repurchased (in shares)				9
Shares repurchased				$ 85
Stock repurchase program, remaining authorized repurchase amount				$ 1,300

Incentive Based Compensation -

Incentive Based Compensation - Stock Options, Restricted Stock Awards and Restricted Stock Units (Details)	6 Months Ended
	Jun. 30, 2020$ / sharesshares
Number of Shares
Outstanding, beginning (in shares) | shares	5,659,731
Granted (in shares) | shares	1,132,808
Options Exercised/Vested (in shares) | shares	(52,333)
Canceled (in shares) | shares	(565,219)
Outstanding, ending (in shares) | shares	6,174,987
Weighted Average Exercise Price
Outstanding, beginning (in dollars per share)	$ 23.55
Granted (in dollars per share)	10.47
Options Exercised (in dollars per share)	7.22
Canceled (in dollars per share)	23.52
Outstanding, ending (in dollars per share)	21.29
Weighted Average Grant Date Fair Value
Weighted average grant date fair value (in dollars per share)	$ 3.82
Restricted Stock Awards & Units
Awards
Outstanding, beginning (in shares) | shares	7,174,386
Granted (in shares) | shares	5,337,796
Stock Exercised/Vested (in shares) | shares	(2,911,712)
Canceled (in shares) | shares	(1,405,754)
Outstanding, ending (in shares) | shares	8,194,716
Weighted Average Grant Date Fair Value
Outstanding, beginning (in dollars per share)	$ 15.88
Granted (in dollars per share)	8.55
Stock Vested (in dollars per share)	15.93
Canceled (in dollars per share)	11.70
Outstanding, ending (in dollars per share)	$ 11.80

Incentive Based Compensation _2

Incentive Based Compensation - Stock-based Performance Unit Awards (Details) - Granted Officer - Performance Unit Awards	6 Months Ended
	Jun. 30, 2020$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	1,038,676
Grant date fair value (in dollars per share) | $ / shares	$ 10.55
Outstanding units (in shares)	1,658,088

Defined Benefit Postretiremen_3

Defined Benefit Postretirement Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Amortization:
Net settlement loss	$ (7)	$ (2)	$ (7)	$ (7)
Estimated future contributions over the remainder of the current year	16		16
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	5	10	9
Interest cost	2	7	5	14
Expected return on plan assets	(2)	(8)	(5)	(16)
Amortization:
– prior service cost (credit)	(2)	(2)	(4)	(4)
– actuarial loss	2	2	5	4
Net settlement loss	14	2	16	2
Net curtailment gain	(3)	0	(3)	0
Net periodic benefit cost	16	6	24	9
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 cost (credit)	(5)	(4)	(9)	(8)
– actuarial loss	1	0	1	0
Net settlement loss	0	0	0	0
Net curtailment gain	(14)	0	(14)	0
Net periodic benefit cost	$ (18)	$ (3)	(21)	$ (6)
Payment for other postretirement benefits			8
Funded Plan
Amortization:
Payment for pension benefits			12
Unfunded Plan
Amortization:
Payment for pension benefits			$ 14

Reclassifications Out of Accu_3

Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit credit	$ 7		$ 2		$ 7	$ 7
Net income	(750)	$ (46)	161	$ 174	(796)	335
Amortization of prior service credit | Reclassification out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit credit	7		6		13	12
Amortization of actuarial loss | Reclassification out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit credit	(3)		(2)		(6)	(4)
Net settlement loss | Reclassification out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit credit	(14)		(2)		(16)	(2)
Net curtailment gain | Reclassification out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit credit	17		0		17	0
Postretirement and postemployment plans | Reclassification out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	$ 7		$ 2		$ 8	$ 6

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Included in operating activities:
Interest paid, net of amounts capitalized	$ 126	$ 128
Income taxes paid to taxing authorities, net of refunds received	4	66
Noncash investing activities:
Increase (decrease) in asset retirement costs	(6)	29
Asset retirement obligations assumed by buyer	0	109
Proceeds from income tax refunds	4	89
Capital expenditures incurred but not yet paid	$ 48	300
Droshky Field
Noncash investing activities:
Asset retirement obligations assumed by buyer		$ 98

Equity Method Investments - Nar

Equity Method Investments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Revenue from related parties	$ 10	$ 11	$ 20	$ 21
Due from related parties	25		25		$ 28
Due to related parties	$ 10		$ 10		$ 11
EGHoldings
Schedule of Equity Method Investments [Line Items]
Ownership percentage	60.00%		60.00%
Alba Plant LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage	52.00%		52.00%
AMPCO
Schedule of Equity Method Investments [Line Items]
Ownership percentage	45.00%		45.00%

Equity Method Investments - Sch

Equity Method Investments - Schedule of Equity Method Investments (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 476	$ 663
EGHoldings
Schedule of Equity Method Investments [Line Items]
Ownership percentage	60.00%
Equity method investments	$ 139	310
Alba Plant LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage	52.00%
Equity method investments	$ 168	163
AMPCO
Schedule of Equity Method Investments [Line Items]
Ownership percentage	45.00%
Equity method investments	$ 169	$ 190

Equity Method Investments - Sum

Equity Method Investments - Summarized Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Equity Method Investments and Joint Ventures [Abstract]
Revenues and other income	$ 111	$ 233	$ 283	$ 453
Income (loss) from operations	(10)	82	(40)	131
Net income (loss)	$ (13)	$ 63	$ (39)	$ 95

Commitments and Contingencies (

Commitments and Contingencies (Details)	Jun. 30, 2020USD ($)
Loss Contingencies [Line Items]
Guarantees recorded	$ 4,000,000
Contingent royalty liability	101,000,000
Contingent capital and expense receivable, noncurrent	25,000,000
Estimated minimum monetary sanctions for Clean Air Act enforcement action	100,000
Performance of Equatorial Guinea LNG Operations, S.A.
Loss Contingencies [Line Items]
Guarantor obligations, maximum exposure	91,000,000
Performance of Alba Plant LLC.
Loss Contingencies [Line Items]
Guarantor obligations, maximum exposure	$ 25,000,000

Uncategorized Items - mro-20200

Label	Element	Value
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Disposal Group, Including Discontinued Operations	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsDisposalGroupIncludingDiscontinuedOperations	$ 0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Disposal Group, Including Discontinued Operations	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsDisposalGroupIncludingDiscontinuedOperations	335,000,000
Cash and Cash Equivalents, at Carrying Value	us-gaap_CashAndCashEquivalentsAtCarryingValue	961,000,000
Cash and Cash Equivalents, at Carrying Value	us-gaap_CashAndCashEquivalentsAtCarryingValue	$ 522,000,000