Business Segment Information - Financial Segment Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Oil and gas production revenues	$ 3,468,000,000	$ 4,288,000,000	$ 10,823,000,000	$ 12,311,000,000
Operating Income	(302,000,000)	1,199,000,000	2,593,000,000	4,382,000,000
Other Income (Expense):
Derivative instrument gains (losses), net	273,000,000	(422,000,000)	79,000,000	(275,000,000)
Other	(1,000,000)	34,000,000	(3,000,000)	78,000,000
General and administrative	(112,000,000)	(120,000,000)	(309,000,000)	(359,000,000)
Acquisition, divestiture, and separation costs	(34,000,000)		(66,000,000)
Financing costs, net	(41,000,000)	(50,000,000)	(103,000,000)	(157,000,000)
NET INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	(217,000,000)	641,000,000	2,191,000,000	3,669,000,000
Total Assets	60,990,000,000	58,641,000,000	60,990,000,000	58,641,000,000	61,637,000,000
United States [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues	1,481,000,000	2,029,000,000	4,515,000,000	5,543,000,000
Operating Income	(988,000,000)	310,000,000	354,000,000	1,607,000,000
Other Income (Expense):
Total Assets	30,613,000,000	29,503,000,000	30,613,000,000	29,503,000,000
Canada [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues	268,000,000	325,000,000	879,000,000	952,000,000
Operating Income	11,000,000	4,000,000	131,000,000	17,000,000
Other Income (Expense):
Total Assets	7,100,000,000	7,083,000,000	7,100,000,000	7,083,000,000
Egypt [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues	910,000,000	1,022,000,000	2,849,000,000	2,924,000,000
Operating Income	481,000,000	658,000,000	1,601,000,000	1,827,000,000
Other Income (Expense):
Total Assets	7,246,000,000	7,142,000,000	7,246,000,000	7,142,000,000
Australia [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues	287,000,000	279,000,000	780,000,000	867,000,000
Operating Income	70,000,000	117,000,000	239,000,000	373,000,000
Other Income (Expense):
Total Assets	9,148,000,000	7,567,000,000	9,148,000,000	7,567,000,000
North Sea [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues	522,000,000	633,000,000	1,800,000,000	2,025,000,000
Operating Income	124,000,000	186,000,000	268,000,000	634,000,000
Other Income (Expense):
Total Assets	6,824,000,000	7,292,000,000	6,824,000,000	7,292,000,000
Other International [Member]
Segment Reporting Information [Line Items]
Oil and gas production revenues
Operating Income		(76,000,000)		(76,000,000)
Other Income (Expense):
Total Assets	$ 59,000,000	$ 54,000,000	$ 59,000,000	$ 54,000,000