CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenues and Other
Oil and condensate sales	$ 850	$ 1,419
Natural-gas sales	366	641
Natural-gas liquids sales	178	232
Gathering, processing, and marketing sales	240	293
Gains (losses) on divestitures and other, net	40	(264)
Total	1,674	2,321
Costs and Expenses
Oil and gas operating	208	296
Oil and gas transportation	242	305
Exploration	126	1,083
Gathering, processing, and marketing	215	254
General and administrative	449	307
Depreciation, depletion, and amortization	1,149	1,256
Other taxes	117	182
Impairments	16	2,783
Other operating expense	16	63
Total	2,538	6,529
Operating Income (Loss)	(864)	(4,208)
Other (Income) Expense
Interest expense	220	216
(Gains) losses on derivatives, net	299	152
Other (income) expense, net	0	47
Total	517	420
Income (Loss) Before Income Taxes	(1,381)	(4,628)
Income tax expense (benefit)	(383)	(1,392)
Net Income (Loss)	(998)	(3,236)
Net income (loss) attributable to noncontrolling interests	36	32
Net Income (Loss) Attributable to Common Stockholders	$ (1,034)	$ (3,268)
Per Common Share
Net income (loss) attributable to common stockholders—basic	$ (2.03)	$ (6.45)
Net income (loss) attributable to common stockholders—diluted	$ (2.03)	$ (6.45)
Average Number of Common Shares Outstanding—Basic	509	507
Average Number of Common Shares Outstanding—Diluted	509	507
Dividends (per common share)	$ 0.05	$ 0.27
Commodity Contract and Interest Rate Swap [Member]
Other (Income) Expense
(Gains) losses on derivatives, net	$ 297	$ 152
Tronox Litigation [Member] | Judicial Ruling [Member]
Other (Income) Expense
Tronox-related contingent loss	$ 0	$ 5