Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Cash flows from operating activities
Net income (loss)		$ 596,980		$ 11,098		$ 453,489
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization		272,933		272,611		211,809
Impairments		15,535		515,458		5,125
Non-cash equity-based compensation expense		4,986		4,445		4,105
Deferred income taxes		2,555		11,346		38,682
Accretion and amortization of long-term obligations, net		(3,262)		17,698		2,736
Equity income, net – affiliates	[1]	(78,717)		(71,251)		(57,836)
Distributions from equity investment earnings – affiliates		82,185		82,054		62,967
(Gain) loss on divestiture and other, net	[2],[3]	14,641		(57,024)		9
Lower of cost or market inventory adjustments		168		443		0
Changes in assets and liabilities:
(Increase) decrease in accounts receivable, net		(48,998)		(4,428)		1,504
Increase (decrease) in accounts and imbalance payables and accrued liabilities, net		58,365		1,006		(35,926)
Change in other items, net		(4,295)		(647)		3,998
Net cash provided by operating activities		913,076		782,809		690,662
Cash flows from investing activities
Capital expenditures		(479,993)		(637,964)		(805,005)
Investments in equity affiliates		(27)		(11,442)		(64,278)
Distributions from equity investments in excess of cumulative earnings – affiliates		21,238	[4]	16,244	[4]	18,055
Proceeds from property insurance claims		17,465		0		0
Net cash used in investing activities		(1,105,534)		(500,277)		(2,740,175)
Cash flows from financing activities
Borrowings, net of debt issuance costs		1,323,198		889,606		1,648,028
Repayments of debt		(900,000)		(611,150)		(650,000)
Increase (decrease) in outstanding checks		2,079		(2,666)		765
Distributions to WGP unitholders	[5]	(374,082)		(306,477)		(228,481)
Net contributions from (distributions to) Anadarko		(23,491)		(49,801)		(16,392)
Above-market component of swap extensions with Anadarko	[5]	45,820		18,449		0
Net cash provided by (used in) financing activities		451,836		(250,051)		2,003,605
Net increase (decrease) in cash and cash equivalents		259,378		32,481		(45,908)
Cash and cash equivalents at beginning of period		99,694		67,213		113,121
Cash and cash equivalents at end of period		359,072		99,694		67,213
Supplemental disclosures
Net distributions to (contributions from) Anadarko of other assets		581		4,632		10,706
Interest paid, net of capitalized interest		107,657		94,720		67,648
Taxes paid (reimbursements received)		838		0		(90)
Capital lease asset transfer	[6]	0		0		4,833
Delaware Basin JV Gathering LLC [Member]
Supplemental disclosures
Acquisition of DBJV from Anadarko		(147,234)		174,276		0
Chipeta Processing LLC [Member]
Cash flows from financing activities
Distributions to Chipeta noncontrolling interest owner		(13,784)		(12,187)		(15,149)
Western Gas Partners, LP [Member]
Cash flows from financing activities
Proceeds from the issuance of common and general partner units, net of offering expenses		0		57,353		691,178
Distributions to noncontrolling interest owners of WES		(294,841)		(233,178)		(176,344)
Western Gas Partners, LP [Member] | Class C Units [Member]
Cash flows from financing activities
Proceeds from the issuance of WES Class C and Series A Preferred units		0		0		750,000
Western Gas Partners, LP [Member] | Series A Preferred Units [Member]
Cash flows from financing activities
Proceeds from the issuance of WES Class C and Series A Preferred units		686,937		0		0
Affiliates [Member]
Cash flows from investing activities
Contributions in aid of construction costs from affiliates		6,135		461		183
Acquisitions		(716,465)		(10,903)		(379,193)
Proceeds from the sale of assets		623		925		402
Affiliates [Member] | Western Gas Partners, LP [Member]
Cash flows from financing activities
Distributions to WGP unitholders	[7]	(5,614)		(2,235)		(1,747)
Third Parties [Member]
Cash flows from investing activities
Acquisitions		0		(3,514)		(1,523,327)
Proceeds from the sale of assets		$ 45,490		$ 145,916		$ 12,988

[1] 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.

[2] Includes losses related to an incident at the DBM complex for the year ended December 31, 2015. See Note 1.

[3] Includes losses related to an incident at the DBM complex for the year ended December 31, 2015. See Note 1.

[4] 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.

[5] See Note 5.

[6] For the year ended December 31, 2014, represents transfers of $4.6 million from other long-term assets associated with the capital lease component of a processing agreement.

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