Income Taxes - Tax Rate Reconciliation Table (details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Related Party Transaction [Line Items]
Income before income taxes	$ 389,406	$ 284,183	$ 169,441
Statutory tax rate	0.00%	0.00%	0.00%
Adjustments Resulting From [Abstract]
State taxes on income attributable to Anadarko's investment in WES (net of federal benefit) Texas margin tax expense (benefit)	2,481	(1,359)	1,258
Income tax expense	2,027us-gaap_IncomeTaxExpenseBenefit	2,305us-gaap_IncomeTaxExpenseBenefit	48,884us-gaap_IncomeTaxExpenseBenefit
Effective tax rate	1.00%	1.00%	29.00%
Western Gas Partners [Member]
Adjustments Resulting From [Abstract]
Federal taxes on income attributable to Anadarko's investment in WES	(454)	3,043	41,557
State taxes on income attributable to Anadarko's investment in WES (net of federal benefit) Texas margin tax expense (benefit)	$ 0	$ 621	$ 6,069

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to state and local income tax expense (benefit).

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