Business Segment Information - Financial Segment Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Oil and gas production revenues		$ 6,383,000,000	$ 12,691,000,000	$ 14,771,000,000
Depreciation, depletion, and amortization:
Recurring		3,855,000,000	4,719,000,000	4,871,000,000
Additional		25,517,000,000	5,001,000,000	995,000,000
Asset retirement obligation accretion		145,000,000	154,000,000	211,000,000
Lease operating expenses		1,854,000,000	2,238,000,000	2,650,000,000
Gathering and transportation		211,000,000	273,000,000	288,000,000
Taxes other than income		282,000,000	577,000,000	772,000,000
Operating Income (Loss)		(25,481,000,000)	(271,000,000)	4,984,000,000
Other Income (Expense):
Other		(17,000,000)	110,000,000	(333,000,000)
Impairments	$ (604,000,000)	(1,920,000,000)	(1,919,000,000)	0
General and administrative		(377,000,000)	(451,000,000)	(481,000,000)
Transaction, reorganization, and separation		(132,000,000)	(67,000,000)	(33,000,000)
Financing costs, net		(299,000,000)	(211,000,000)	(229,000,000)
NET INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES		(28,226,000,000)	(2,809,000,000)	3,908,000,000
Net property and equipment	41,560,000,000	14,119,000,000	41,560,000,000	44,167,000,000
Total Assets	55,952,000,000	18,842,000,000	55,952,000,000	51,966,000,000
Additions to Net Property and Equipment	10,697,000,000	4,454,000,000	10,697,000,000	9,903,000,000
United States [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues		2,637,000,000	5,744,000,000	6,902,000,000
Depreciation, depletion, and amortization:
Recurring		1,522,000,000	2,170,000,000	2,338,000,000
Additional		19,537,000,000	4,412,000,000	552,000,000
Asset retirement obligation accretion		28,000,000	43,000,000	94,000,000
Lease operating expenses		739,000,000	921,000,000	1,320,000,000
Gathering and transportation		68,000,000	93,000,000	84,000,000
Taxes other than income		184,000,000	350,000,000	335,000,000
Operating Income (Loss)		(19,441,000,000)	(2,245,000,000)	2,179,000,000
Other Income (Expense):
Net property and equipment	24,627,000,000	5,826,000,000	24,627,000,000	27,010,000,000
Total Assets	26,853,000,000	7,113,000,000	26,853,000,000	29,940,000,000
Additions to Net Property and Equipment	7,294,000,000	2,454,000,000	7,294,000,000	6,404,000,000
Canada [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues		498,000,000	1,092,000,000	1,224,000,000
Depreciation, depletion, and amortization:
Recurring		312,000,000	400,000,000	505,000,000
Additional		3,667,000,000
Asset retirement obligation accretion		43,000,000	39,000,000	49,000,000
Lease operating expenses		244,000,000	384,000,000	459,000,000
Gathering and transportation		89,000,000	123,000,000	155,000,000
Taxes other than income		26,000,000	31,000,000	45,000,000
Operating Income (Loss)		(3,883,000,000)	115,000,000	11,000,000
Other Income (Expense):
Net property and equipment	6,107,000,000	1,314,000,000	6,107,000,000	6,058,000,000
Total Assets	6,640,000,000	1,465,000,000	6,640,000,000	6,952,000,000
Additions to Net Property and Equipment	963,000,000	324,000,000	963,000,000	1,082,000,000
Egypt [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues		1,968,000,000	3,539,000,000	3,917,000,000
Depreciation, depletion, and amortization:
Recurring		1,275,000,000	1,151,000,000	1,005,000,000
Additional		281,000,000
Lease operating expenses		522,000,000	499,000,000	471,000,000
Gathering and transportation		45,000,000	40,000,000	42,000,000
Taxes other than income		9,000,000	11,000,000	8,000,000
Operating Income (Loss)		(164,000,000)	1,838,000,000	2,391,000,000
Other Income (Expense):
Net property and equipment	5,700,000,000	3,998,000,000	5,700,000,000	5,454,000,000
Total Assets	7,292,000,000	6,249,000,000	7,292,000,000	8,121,000,000
Additions to Net Property and Equipment	1,397,000,000	915,000,000	1,397,000,000	1,309,000,000
North Sea [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues		1,280,000,000	2,316,000,000	2,728,000,000
Depreciation, depletion, and amortization:
Recurring		746,000,000	998,000,000	1,022,000,000
Additional		2,032,000,000	589,000,000	367,000,000
Asset retirement obligation accretion		74,000,000	72,000,000	68,000,000
Lease operating expenses		349,000,000	434,000,000	400,000,000
Gathering and transportation		9,000,000	17,000,000	7,000,000
Taxes other than income		63,000,000	185,000,000	384,000,000
Operating Income (Loss)		(1,993,000,000)	21,000,000	480,000,000
Other Income (Expense):
Net property and equipment	5,103,000,000	2,929,000,000	5,103,000,000	5,622,000,000
Total Assets	6,101,000,000	3,951,000,000	6,101,000,000	6,902,000,000
Additions to Net Property and Equipment	1,071,000,000	733,000,000	1,071,000,000	1,084,000,000
Other International [Member]
Depreciation, depletion, and amortization:
Recurring				1,000,000
Additional				76,000,000
Operating Income (Loss)				(77,000,000)
Other Income (Expense):
Net property and equipment	23,000,000	52,000,000	23,000,000	23,000,000
Total Assets	46,000,000	64,000,000	46,000,000	51,000,000
Additions to Net Property and Equipment	$ (28,000,000)	$ 28,000,000	$ (28,000,000)	$ 24,000,000