Business Segment Information - Financial Segment Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Oil and gas production revenues	$ 3,708,000,000	$ 4,001,000,000	$ 7,355,000,000	$ 8,022,000,000
Operating Income (Loss)	1,346,000,000	1,559,000,000	2,895,000,000	3,181,000,000
Other Income (Expense):
Derivative instrument gains (losses), net	(174,000,000)	247,000,000	(194,000,000)	147,000,000
Other	(50,000,000)	20,000,000	(2,000,000)	45,000,000
General and administrative	(94,000,000)	(126,000,000)	(199,000,000)	(238,000,000)
Acquisition, divestiture, and separation costs	(14,000,000)		(30,000,000)
Financing costs, net	(35,000,000)	(52,000,000)	(62,000,000)	(107,000,000)
NET INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	979,000,000	1,648,000,000	2,408,000,000	3,028,000,000
Total Assets	61,171,000,000	61,622,000,000	61,171,000,000	61,622,000,000	61,637,000,000
United States [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues	1,529,000,000	1,836,000,000	3,034,000,000	3,513,000,000
Operating Income (Loss)	679,000,000	712,000,000	1,342,000,000	1,298,000,000
Other Income (Expense):
Total Assets	31,547,000,000	33,376,000,000	31,547,000,000	33,376,000,000
Canada [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues	293,000,000	329,000,000	611,000,000	627,000,000
Operating Income (Loss)	47,000,000	14,000,000	119,000,000	11,000,000
Other Income (Expense):
Total Assets	6,842,000,000	6,927,000,000	6,842,000,000	6,927,000,000
Egypt [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues	989,000,000	893,000,000	1,939,000,000	1,902,000,000
Operating Income (Loss)	585,000,000	512,000,000	1,121,000,000	1,170,000,000
Other Income (Expense):
Total Assets	7,264,000,000	6,951,000,000	7,264,000,000	6,951,000,000
Australia [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues	237,000,000	291,000,000	493,000,000	588,000,000
Operating Income (Loss)	74,000,000	119,000,000	169,000,000	254,000,000
Other Income (Expense):
Total Assets	8,763,000,000	7,124,000,000	8,763,000,000	7,124,000,000
North Sea [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues	660,000,000	652,000,000	1,278,000,000	1,392,000,000
Operating Income (Loss)	(39,000,000)	202,000,000	144,000,000	448,000,000
Other Income (Expense):
Total Assets	6,713,000,000	7,114,000,000	6,713,000,000	7,114,000,000
Other International [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues	0		0
Operating Income (Loss)	0		0
Other Income (Expense):
Total Assets	$ 42,000,000	$ 130,000,000	$ 42,000,000	$ 130,000,000