Business Segment Information - Financial Segment Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Oil and Gas Production Revenues	$ 1,512	$ 1,087
Operating Income (Loss)	365	(165)
Gain (loss) on divestitures	341	(1)
Other Income (Expense):
Other	25	(3)
General and administrative	(103)	(93)
Transaction, reorganization, and separation	10	(15)
Financing costs, net	(100)	(105)
NET INCOME (LOSS) BEFORE INCOME TAXES	538	(382)
Total Assets	22,610	24,734	$ 22,519
Operating Segments [Member] | United States [Member]
Segment Reporting Information [Line Items]
Oil and Gas Production Revenues	552	409
Operating Income (Loss)	60	(159)
Other Income (Expense):
Total Assets	12,361	12,726
Asset impairments	15	40
Operating Segments [Member] | Canada [Member]
Segment Reporting Information [Line Items]
Oil and Gas Production Revenues	102	83
Operating Income (Loss)	(13)	(62)
Other Income (Expense):
Total Assets	1,556	2,118
Asset impairments	8	2
Operating Segments [Member] | Egypt [Member]
Segment Reporting Information [Line Items]
Oil and Gas Production Revenues	591	392
Operating Income (Loss)	301	42
Other Income (Expense):
Total Assets	5,006	5,527
Operating Segments [Member] | North Sea [Member]
Segment Reporting Information [Line Items]
Oil and Gas Production Revenues	267	203
Operating Income (Loss)	38	14
Other Income (Expense):
Total Assets	3,634	4,314
Other International [Member]
Segment Reporting Information [Line Items]
Oil and Gas Production Revenues	0	0
Operating Income (Loss)	(21)	0
Other Income (Expense):
Total Assets	$ 53	$ 49