Segment Information - Selected Financial Information for Anadarko's Reporting Segments Table (Detail) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015		Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Revenues		$ 1,985	$ 2,637		$ 3,619	$ 5,222
Other		34	90		72	160
Total revenues and other (1)		1,915	2,636		3,589	4,957
Operating costs and expenses (2)		2,247	2,546		4,785	9,075
Net cash from settlement of commodity derivatives					(165)	(172)
Other (income) expense, net		(55)	15		(55)	62
Net income (loss) attributable to noncontrolling interests		81	47		117	79
Total expenses and other		1,143	1,179		2,119	2,549
Consolidated Adjusted EBITDAX		880	1,548		1,580	2,834
(Gains) Losses on Derivatives, Net [Member] | Commodity Contract [Member]
Segment Reporting Information [Line Items]
Net cash from settlement of commodity derivatives		(60)	(82)		(163)	(172)
Gathering, Processing, and Marketing Sales [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]
Segment Reporting Information [Line Items]
Total (gains) losses on derivatives, net included in marketing revenue, less net cash from settlement		4			8	1
Excluding Gains Losses On Divestitures Net [Member]
Segment Reporting Information [Line Items]
Total revenues and other (1)	[1]	2,019	2,727		3,691	5,382
Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses (2)	[2]	1,121	1,199		2,164	2,602
Excluding Certain Other Nonoperating Items [Member]
Segment Reporting Information [Line Items]
Other (income) expense, net		1	15	[3]	1	40	[3]
Other and Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues		0	0		0	0
Other		34	90		72	160
Total expenses and other		(124)	(126)		(316)	(228)
Consolidated Adjusted EBITDAX		(73)	(18)		(83)	(74)
Other and Intersegment Eliminations [Member] | (Gains) Losses on Derivatives, Net [Member] | Commodity Contract [Member]
Segment Reporting Information [Line Items]
Net cash from settlement of commodity derivatives		(60)	(82)		(163)	(172)
Other and Intersegment Eliminations [Member] | Excluding Gains Losses On Divestitures Net [Member]
Segment Reporting Information [Line Items]
Total revenues and other (1)	[1]	(197)	(144)		(399)	(302)
Other and Intersegment Eliminations [Member] | Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses (2)	[2]	(65)	(59)		(154)	(96)
Other and Intersegment Eliminations [Member] | Excluding Certain Other Nonoperating Items [Member]
Segment Reporting Information [Line Items]
Other (income) expense, net		1	15	[3]	1	40	[3]
Other and Intersegment Eliminations [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		(231)	(234)		(471)	(462)
Oil and Gas Exploration and Production Reporting Segment [Member]
Segment Reporting Information [Line Items]
Revenues		1,033	1,356		1,744	2,426
Oil and Gas Exploration and Production Reporting Segment [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		567	885		1,168	2,002
Oil and Gas Exploration and Production Reporting Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total expenses and other		790	832		1,563	1,834
Consolidated Adjusted EBITDAX		810	1,409		1,349	2,594
Oil and Gas Exploration and Production Reporting Segment [Member] | Operating Segments [Member] | Excluding Gains Losses On Divestitures Net [Member]
Segment Reporting Information [Line Items]
Total revenues and other (1)	[1]	1,600	2,241		2,912	4,428
Oil and Gas Exploration and Production Reporting Segment [Member] | Operating Segments [Member] | Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses (2)	[2]	790	832		1,563	1,834
Midstream Reporting Segment [Member]
Segment Reporting Information [Line Items]
Revenues		141	191		266	365
Midstream Reporting Segment [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		340	303		642	605
Midstream Reporting Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net income (loss) attributable to noncontrolling interests		81	47		117	79
Total expenses and other		300	281		519	553
Consolidated Adjusted EBITDAX		181	213		389	417
Midstream Reporting Segment [Member] | Operating Segments [Member] | Excluding Gains Losses On Divestitures Net [Member]
Segment Reporting Information [Line Items]
Total revenues and other (1)	[1]	481	494		908	970
Midstream Reporting Segment [Member] | Operating Segments [Member] | Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses (2)	[2]	219	234		402	474
Marketing Reporting Segment [Member]
Segment Reporting Information [Line Items]
Revenues		811	1,090		1,609	2,431
Marketing Reporting Segment [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		(676)	(954)		(1,339)	(2,145)
Marketing Reporting Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total expenses and other		177	192		353	390
Consolidated Adjusted EBITDAX		(38)	(56)		(75)	(103)
Marketing Reporting Segment [Member] | Operating Segments [Member] | Gathering, Processing, and Marketing Sales [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]
Segment Reporting Information [Line Items]
Total (gains) losses on derivatives, net included in marketing revenue, less net cash from settlement		4			8	1
Marketing Reporting Segment [Member] | Operating Segments [Member] | Excluding Gains Losses On Divestitures Net [Member]
Segment Reporting Information [Line Items]
Total revenues and other (1)	[1]	135	136		270	286
Marketing Reporting Segment [Member] | Operating Segments [Member] | Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses (2)	[2]	$ 177	$ 192		$ 353	$ 390

[1] Total revenues and other excludes gains (losses) on divestitures, net since these gains and losses are excluded from Adjusted EBITDAX.

[2] Operating costs and expenses excludes exploration expense, DD&A, impairments, restructuring charges, and other operating expense since these expenses are excluded from Adjusted EBITDAX.

[3] Other (income) expense, net excludes certain other nonoperating items since these items are excluded from Adjusted EBITDAX.