Business Segment Information - Financial Segment Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Oil and Gas Production Revenues	$ 3,647	$ 4,021
Operating Income	1,549	1,622
Other Income (Expense):
Derivative instruments losses, net	(20)	(100)
Other	48	25
General and administrative	(119)	(112)
Acquisition, divestitures, and transition	(2)
Financing costs, net	27	55
NET INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	1,429	1,380
Total assets	61,121	60,063	61,637
United States [Member]
Segment Reporting Information [Line Items]
Oil and Gas Production Revenues	1,505	1,677
Operating Income	663	585
Other Income (Expense):
Total assets	30,618	32,205
Canada [Member]
Segment Reporting Information [Line Items]
Oil and Gas Production Revenues	318	297
Operating Income	71	(5)
Other Income (Expense):
Total assets	7,102	6,935
Egypt [Member]
Segment Reporting Information [Line Items]
Oil and Gas Production Revenues	950	1,009
Operating Income	536	658
Other Income (Expense):
Total assets	7,350	7,031
Australia [Member]
Segment Reporting Information [Line Items]
Oil and Gas Production Revenues	256	298
Operating Income	96	138
Other Income (Expense):
Total assets	8,403	6,729
North Sea [Member]
Segment Reporting Information [Line Items]
Oil and Gas Production Revenues	618	740
Operating Income	183	246
Other Income (Expense):
Total assets	7,599	7,053
Other International [Member]
Other Income (Expense):
Total assets	$ 49	$ 110