Consolidated Statements of Cash Flows - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2015		Jun. 30, 2014
Cash flows from operating activities
Net income		$ 198,512		$ 195,677	[1]
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and impairments		136,253		87,390	[1]
Non-cash equity-based compensation expense		2,262		2,247	[1]
Deferred income taxes		1,825		2,218	[1]
Accretion and amortization of long-term obligations, net		7,070		1,358	[1]
Equity income, net	[2],[3],[4]	(37,161)		(22,259)	[1]
Distributions from equity investment earnings	[3]	39,034		26,793	[1]
Changes in assets and liabilities:
(Increase) decrease in accounts receivable, net		(46,170)		(23,772)	[1]
Increase (decrease) in accounts and natural gas imbalance payables and accrued liabilities, net		287		3,320	[1]
Change in other items, net		(1,543)		4,670	[1]
Net cash provided by operating activities		300,369		277,642	[1]
Cash flows from investing activities
Capital expenditures		(338,178)		(390,506)	[1]
Investments in equity affiliates		(6,770)		(60,102)	[1]
Distributions from equity investments in excess of cumulative earnings	[3]	8,538	[5]	9,848	[1]
Net cash used in investing activities		(349,170)		(801,530)	[1]
Cash flows from financing activities
Borrowings, net of debt issuance costs		769,694		1,076,895	[1]
Repayments of debt		(521,150)		(480,000)	[1]
Increase (decrease) in outstanding checks		(2,327)		2,517	[1]
Distributions to WGP unitholders		(143,386)		(105,347)	[1]
Net contributions from Anadarko		30,096		39,033	[1]
Net cash provided by financing activities		70,850		532,945	[1]
Net increase (decrease) in cash and cash equivalents		22,049		9,057	[1]
Cash and cash equivalents at beginning of period		67,213	[6]	113,085	[1]
Cash and cash equivalents at end of period		89,262		122,142	[1]
Supplemental disclosures
Net distributions to (contributions from) Anadarko of other assets		4,726		(43)	[1]
Interest paid, net of capitalized interest		42,167		26,346	[1]
Taxes paid (reimbursements received)		(138)		(340)	[1]
Capital lease asset transfer	[7]	0		4,833	[1]
Western Gas Partners, LP [Member]
Cash flows from financing activities
Proceeds from the issuance of WES common units, net of offering expenses		57,376		91,690	[1]
Distributions to noncontrolling interest owners of WES		(112,278)		(83,894)	[1]
Delaware Basin JV Gathering LLC [Member]
Cash flows from operating activities
Net income				7,756
Adjustments to reconcile net income to net cash provided by operating activities:
Equity income, net				0
Supplemental disclosures
Acquisition of DBJV from Anadarko	[8]	174,276		0	[1]
Chipeta Processing LLC [Member]
Cash flows from financing activities
Distributions to Chipeta noncontrolling interest owners		(7,175)		(7,949)	[1]
Affiliates [Member]
Cash flows from investing activities
Contributions in aid of construction costs from affiliates		0		182	[1]
Acquisitions		(9,968)		(360,952)	[1]
Proceeds from the sale of assets		700		0	[1]
Affiliates [Member] | Western Gas Partners, LP [Member]
Cash flows from financing activities
Distributions to WGP unitholders	[9]	(1,080)		(743)
Third Parties [Member]
Cash flows from investing activities
Acquisitions		(3,514)		0	[1]
Proceeds from the sale of assets		$ 22		$ 0	[1]

[1] Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.

[2] Income earned from equity investments is classified as affiliate. See Note 1.

[3] Income earned on, distributions from and contributions to equity investments are classified as affiliate. See Note 1.

[4] Represents amounts earned or incurred on and subsequent to the date of acquisition of WES assets, as well as amounts earned or incurred by Anadarko on a historical basis related to WES assets prior to the acquisition of such assets by WES, recognized under gathering, treating or processing agreements, and purchase and sale agreements.

[5] Distributions in excess of cumulative earnings, classified as investing cash flows in the consolidated statements of cash flows, is calculated on an individual investment basis.

[6] Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.

[7] For the six months ended June 30, 2014, represents transfers of $4.6 million from other long-term assets associated with the capital lease component of a processing agreement.

[8] See Note 2.

[9] Represents distributions paid to other subsidiaries of Anadarko under WES’s partnership agreement (see Note 3 and Note 4).