CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues and Other
Oil sales	$ 2,127	$ 1,663
Natural-gas sales	247	502
Natural-gas liquids sales	292	289
Gathering, processing, and marketing sales	360	444
Gains (losses) on divestitures and other, net	19	869
Total	3,045	3,767
Costs and Expenses
Oil and gas operating	276	256
Oil and gas transportation	196	249
Exploration	168	1,084
Gathering, processing, and marketing	237	350
General and administrative	278	263
Depreciation, depletion, and amortization	990	1,115
Production, property, and other taxes	190	155
Impairments	19	373
Other operating expense	140	22
Total	2,494	3,867
Operating Income (Loss)	551	(100)
Other (Income) Expense
Interest expense	228	223
(Gains) losses on derivatives, net	36	(147)
Other (income) expense, net	(12)	2
Total	251	78
Income (Loss) Before Income Taxes	300	(178)
Income tax expense (benefit)	126	97
Net Income (Loss)	174	(275)
Net income (loss) attributable to noncontrolling interests	53	43
Net Income (Loss) Attributable to Common Stockholders	$ 121	$ (318)
Per Common Share
Net income (loss) attributable to common stockholders—basic (in usd per share)	$ 0.23	$ (0.58)
Net income (loss) attributable to common stockholders—diluted (in usd per share)	$ 0.22	$ (0.58)
Average Number of Common Shares Outstanding—Basic	518	551
Average Number of Common Shares Outstanding—Diluted	519	551
Dividends (in usd per share)	$ 0.25	$ 0.05
Commodity Contract and Interest Rate Swap [Member]
Other (Income) Expense
(Gains) losses on derivatives, net	$ 35	$ (147)