Segment Information - Selected Financial Information for Anadarko's Reporting Segments Table (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenues		$ 9,486	$ 16,375	$ 14,867
Other		234	204	184
Total revenues and other (1)		8,698	18,470	14,581
Operating costs and expenses		17,507	13,067	11,248
Net cash from settlement of commodity derivatives		(335)	(371)	(85)
Other (income) expense, net		149	20	89
Net income (loss) attributable to noncontrolling interests		(120)	187	140
Total expenses and other		4,783	5,753	5,174
Adjusted EBITDAX		4,936	10,830	9,873
Net properties and equipment		33,751	41,589	40,929
Capital expenditures		5,888	9,256	8,523
Goodwill		5,395	5,576	5,492
(Gains) Losses on Derivatives, net [Member] | Commodity Derivatives [Member]
Segment Reporting Information [Line Items]
Net cash from settlement of commodity derivatives		(335)	(377)	(95)
Gathering, Processing, and Marketing Sales [Member] | Commodity Derivatives [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		(1)	4	(4)
Excluding Gains Losses On Divestitures Net [Member]
Segment Reporting Information [Line Items]
Total revenues and other (1)	[1]	9,720	16,579	15,051
Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses	[2]	5,111	5,945	5,150
Excluding Certain Other Nonoperating Items [Member]
Segment Reporting Information [Line Items]
Other (income) expense, net	[3]	127	(2)	(21)
Other and Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Other		234	204	184
Total expenses and other		(294)	(362)	(96)
Adjusted EBITDAX		(381)	(226)	(371)
Net properties and equipment		2,133	2,175	2,103
Capital expenditures		89	173	267
Goodwill		0	0	0
Other and Intersegment Eliminations [Member] | (Gains) Losses on Derivatives, net [Member] | Commodity Derivatives [Member]
Segment Reporting Information [Line Items]
Net cash from settlement of commodity derivatives		(335)	(377)	(95)
Other and Intersegment Eliminations [Member] | Excluding Gains Losses On Divestitures Net [Member]
Segment Reporting Information [Line Items]
Total revenues and other (1)	[1]	(675)	(588)	(467)
Other and Intersegment Eliminations [Member] | Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses	[2]	(86)	17	20
Other and Intersegment Eliminations [Member] | Excluding Certain Other Nonoperating Items [Member]
Segment Reporting Information [Line Items]
Other (income) expense, net	[3]	127	(2)	(21)
Other and Intersegment Eliminations [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		(909)	(792)	(651)
Oil and Gas Exploration and Production Reporting Segment [Member]
Segment Reporting Information [Line Items]
Revenues		4,734	8,603	7,090
Oil and Gas Exploration and Production Reporting Segment [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		3,178	6,225	6,405
Oil and Gas Exploration and Production Reporting Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total expenses and other		3,456	4,216	3,635
Adjusted EBITDAX		4,456	10,612	9,860
Net properties and equipment		25,742	32,717	33,409
Capital expenditures		5,029	7,934	7,008
Goodwill		4,945	5,123	5,317
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]	7,912	14,828	13,495
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]	3,456	4,216	3,635
Midstream Reporting Segment [Member]
Segment Reporting Information [Line Items]
Revenues		727	484	387
Midstream Reporting Segment [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		1,207	1,338	1,105
Midstream Reporting Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net income (loss) attributable to noncontrolling interests		(120)	187	140
Total expenses and other		878	1,159	983
Adjusted EBITDAX		1,056	663	509
Net properties and equipment		5,876	6,697	5,408
Capital expenditures		770	1,149	1,248
Goodwill		450	453	175
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]	1,934	1,822	1,492
Midstream Reporting Segment [Member] | Operating Segments [Member] | Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses	[2]	998	972	843
Marketing Reporting Segment [Member]
Segment Reporting Information [Line Items]
Revenues		4,025	7,288	7,390
Marketing Reporting Segment [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		(3,476)	(6,771)	(6,859)
Marketing Reporting Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total expenses and other		743	740	652
Adjusted EBITDAX		(195)	(219)	(125)
Net properties and equipment		0	0	9
Capital expenditures		0	0	0
Goodwill		0	0	0
Marketing Reporting Segment [Member] | Operating Segments [Member] | Gathering, Processing, and Marketing Sales [Member] | Commodity Derivatives [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		(1)	4	(4)
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]	549	517	531
Marketing Reporting Segment [Member] | Operating Segments [Member] | Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses	[2]	$ 743	$ 740	$ 652

[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, 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.