Segment Information - Selected Financial Information for Anadarko's Reporting Segments Table (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Revenues		$ 1,634	$ 2,585
Other		38	70
Total revenues and other (1)		1,674	2,321
Operating costs and expenses (2)		2,538	6,529
Net cash from settlement of commodity derivatives		(105)	(91)
Other (income) expense, net		0	47
Net income (loss) attributable to noncontrolling interests		36	32
Total expenses and other		976	1,370
Consolidated Adjusted EBITDAX		700	1,286
(Gains) Losses on Derivatives, Net [Member] | Commodity Contract [Member]
Segment Reporting Information [Line Items]
Net cash from settlement of commodity derivatives		(103)	(90)
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	1
Excluding Gains Losses On Divestitures Net [Member]
Segment Reporting Information [Line Items]
Total revenues and other (1)	[1]	1,672	2,655
Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses (2)	[2]	1,043	1,403
Excluding Certain Other Nonoperating Items [Member]
Segment Reporting Information [Line Items]
Other (income) expense, net		0	25	[3]
Other and Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues		0	0
Other		38	70
Total expenses and other		(192)	(102)
Consolidated Adjusted EBITDAX		(10)	(56)
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		(103)	(90)
Other and Intersegment Eliminations [Member] | Excluding Gains Losses On Divestitures Net [Member]
Segment Reporting Information [Line Items]
Total revenues and other (1)	[1]	(202)	(158)
Other and Intersegment Eliminations [Member] | Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses (2)	[2]	(89)	(37)
Other and Intersegment Eliminations [Member] | Excluding Certain Other Nonoperating Items [Member]
Segment Reporting Information [Line Items]
Other (income) expense, net		0	25	[3]
Other and Intersegment Eliminations [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		(240)	(228)
Oil and Gas Exploration and Production Reporting Segment [Member]
Segment Reporting Information [Line Items]
Revenues		711	1,070
Oil and Gas Exploration and Production Reporting Segment [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		601	1,117
Oil and Gas Exploration and Production Reporting Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total expenses and other		773	1,002
Consolidated Adjusted EBITDAX		539	1,185
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]	1,312	2,187
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]	773	1,002
Midstream Reporting Segment [Member]
Segment Reporting Information [Line Items]
Revenues		125	174
Midstream Reporting Segment [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		302	302
Midstream Reporting Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net income (loss) attributable to noncontrolling interests		36	32
Total expenses and other		219	272
Consolidated Adjusted EBITDAX		208	204
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]	427	476
Midstream Reporting Segment [Member] | Operating Segments [Member] | Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses (2)	[2]	183	240
Marketing Reporting Segment [Member]
Segment Reporting Information [Line Items]
Revenues		798	1,341
Marketing Reporting Segment [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenues		(663)	(1,191)
Marketing Reporting Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total expenses and other		176	198
Consolidated Adjusted EBITDAX		(37)	(47)
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	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	150
Marketing Reporting Segment [Member] | Operating Segments [Member] | Excluding Certain Items [Member]
Segment Reporting Information [Line Items]
Operating costs and expenses (2)	[2]	$ 176	$ 198

[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.