CONSOLIDATED STATEMENTS OF INCOME (USD $) Share data in Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues and Other
Natural-gas sales	$ 3,388,000,000	$ 2,444,000,000	$ 3,300,000,000
Oil and condensate sales	9,178,000,000	8,728,000,000	8,072,000,000
Natural-gas liquids sales	1,262,000,000	1,224,000,000	1,462,000,000
Gathering, processing, and marketing sales	1,039,000,000	911,000,000	1,048,000,000
Gains (losses) on divestitures and other, net	(286,000,000)	104,000,000	85,000,000
Total	14,581,000,000	13,411,000,000	13,967,000,000
Costs and Expenses
Oil and gas operating	1,092,000,000	976,000,000	993,000,000
Oil and gas transportation and other	1,022,000,000	955,000,000	891,000,000
Exploration	1,329,000,000	1,946,000,000	1,076,000,000
Gathering, processing, and marketing	869,000,000	763,000,000	791,000,000
General and administrative	1,090,000,000	1,246,000,000	1,060,000,000
Depreciation, depletion, and amortization	3,927,000,000	3,964,000,000	3,830,000,000
Other taxes	1,077,000,000	1,224,000,000	1,492,000,000
Impairments	794,000,000	389,000,000	1,774,000,000
Algeria exceptional profits tax settlement	33,000,000	(1,797,000,000)	0
Deepwater Horizon settlement and related costs	15,000,000	18,000,000	3,930,000,000
Total	11,248,000,000	9,684,000,000	15,837,000,000
Operating Income (Loss)	3,333,000,000	3,727,000,000	(1,870,000,000)
Other (Income) Expense
Interest expense	686,000,000	742,000,000	839,000,000
Statement [Line Items]
(Gains) losses on derivatives, net	(392,000,000)	(308,000,000)	469,000,000
Other (income) expense, net	89,000,000	(4,000,000)	4,000,000
Tronox-related contingent loss	850,000,000	(250,000,000)	250,000,000
Total	1,227,000,000	162,000,000	1,554,000,000
Income (Loss) Before Income Taxes	2,106,000,000	3,565,000,000	(3,424,000,000)
Income tax expense (benefit)	1,165,000,000	1,120,000,000	(856,000,000)
Net Income (Loss)	941,000,000	2,445,000,000	(2,568,000,000)
Net income attributable to noncontrolling interests	140,000,000	54,000,000	81,000,000
Net Income (Loss) Attributable to Common Stockholders	801,000,000	2,391,000,000	(2,649,000,000)
Per Common Share
Net income (loss) attributable to common stockholders—basic	$ 1.58	$ 4.76	$ (5.32)
Net income (loss) attributable to common stockholders—diluted	$ 1.58	$ 4.74	$ (5.32)
Average Number of Common Shares Outstanding—Basic	502	500	498
Average Number of Common Shares Outstanding—Diluted	505	502	498
Dividends (per Common Share)	$ 0.54	$ 0.36	$ 0.36
Commodity Contract and Interest-Rate Swap [Member]
Statement [Line Items]
(Gains) losses on derivatives, net	$ (398,000,000)	$ (326,000,000)	$ 461,000,000