Segment Information - Selected Financial Information for Anadarko's Reporting Segments Table (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016		Sep. 30, 2015
Segment Reporting Information [Line Items]
Revenues		$ 2,251	$ 2,230	$ 5,870		$ 7,452
Other		56	36	128		196
Total revenues and other (1)		1,893	1,688	5,482		6,645
Operating costs and expenses (2)		2,686	4,237	7,471		13,312
Net cash from settlement of commodity derivatives				(229)		(251)
Other (income) expense, net		(31)	47	(86)		109
Net income (loss) attributable to noncontrolling interests		83	75	200		154
Total expenses and other		1,163	1,337	3,282		3,886
Consolidated Adjusted EBITDAX		1,144	928	2,724		3,762
(Gains) Losses on Derivatives, Net [Member] | Commodity Contract [Member]
Segment Reporting Information [Line Items]
Net cash from settlement of commodity derivatives		(63)	(79)	(226)		(251)
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			(1)	8
Excluding Gains Losses On Divestitures Net [Member]
Segment Reporting Information [Line Items]
Total revenues and other (1)	[1]	2,307	2,266	5,998		7,648
Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses (2)	[2]	1,174	1,294	3,338		3,896
Excluding Certain Other Nonoperating Items [Member]
Segment Reporting Information [Line Items]
Other (income) expense, net		(31)	47	(30)	[3]	87	[3]
Other and Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Other		56	36	128		196
Total expenses and other		(173)	(46)	(489)		(274)
Consolidated Adjusted EBITDAX		(17)	(151)	(100)		(225)
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		(63)	(79)	(226)		(251)
Other and Intersegment Eliminations [Member] | Excluding Gains Losses On Divestitures Net [Member]
Segment Reporting Information [Line Items]
Total revenues and other (1)	[1]	(190)	(197)	(589)		(499)
Other and Intersegment Eliminations [Member] | Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses (2)	[2]	(79)	(14)	(233)		(110)
Other and Intersegment Eliminations [Member] | Excluding Certain Other Nonoperating Items [Member]
Segment Reporting Information [Line Items]
Other (income) expense, net		(31)	47	(30)	[3]	87	[3]
Other and Intersegment Eliminations [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		(246)	(233)	(717)		(695)
Oil and Gas Exploration and Production Reporting Segment [Member]
Segment Reporting Information [Line Items]
Revenues		1,109	1,067	2,853		3,493
Oil and Gas Exploration and Production Reporting Segment [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		717	750	1,885		2,752
Oil and Gas Exploration and Production Reporting Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total expenses and other		807	840	2,370		2,674
Consolidated Adjusted EBITDAX		1,019	977	2,368		3,571
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]	1,826	1,817	4,738		6,245
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]	807	840	2,370		2,674
Midstream Reporting Segment [Member]
Segment Reporting Information [Line Items]
Revenues		174	195	440		560
Midstream Reporting Segment [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		370	315	1,012		920
Midstream Reporting Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net income (loss) attributable to noncontrolling interests		83	75	200		154
Total expenses and other		356	362	875		915
Consolidated Adjusted EBITDAX		188	148	577		565
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]	544	510	1,452		1,480
Midstream Reporting Segment [Member] | Operating Segments [Member] | Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses (2)	[2]	273	287	675		761
Marketing Reporting Segment [Member]
Segment Reporting Information [Line Items]
Revenues		968	968	2,577		3,399
Marketing Reporting Segment [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		(841)	(832)	(2,180)		(2,977)
Marketing Reporting Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total expenses and other		173	181	526		571
Consolidated Adjusted EBITDAX		(46)	(46)	(121)		(149)
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			(1)	8
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]	127	136	397		422
Marketing Reporting Segment [Member] | Operating Segments [Member] | Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses (2)	[2]	$ 173	$ 181	$ 526		$ 571

[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.