Consolidated Statements of Cash Flows - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018		Mar. 31, 2017
Cash flows from operating activities
Net income (loss)		$ 150,488		$ 102,661
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization		76,842		69,702
Impairments		148		164,742
Non-cash equity-based compensation expense		1,630		1,269
Deferred income taxes		1,331		3,128
Accretion and amortization of long-term obligations, net		2,103		1,268
Equity income, net – affiliates	[1]	(20,424)		(19,461)
Distributions from equity investment earnings – affiliates		20,941		19,114
(Gain) loss on divestiture and other, net	[2],[3]	(116)		(119,487)
Lower of cost or market inventory adjustments		143		45
Changes in assets and liabilities:
(Increase) decrease in accounts receivable, net		(28,647)		(1,530)
Increase (decrease) in accounts and imbalance payables and accrued liabilities, net		27,307		(29,935)
Change in other items, net		9,170		157
Net cash provided by operating activities		240,916		191,673
Cash flows from investing activities
Capital expenditures		(302,297)		(125,944)
Distributions from equity investments in excess of cumulative earnings – affiliates		8,013	[4]	3,453
Proceeds from property insurance claims		0		24,000
Net cash used in investing activities		(294,168)		(252,434)
Cash flows from financing activities
Borrowings, net of debt issuance costs		1,337,517		(11)
Repayments of debt		(630,000)		0
Increase (decrease) in outstanding checks		(6,684)		1,024
Distributions to WGP unitholders	[5]	(120,140)		(101,254)
Net contributions from (distributions to) Anadarko		0		(14)
Above-market component of swap agreements with Anadarko	[5]	14,282		12,297
Net cash provided by (used in) financing activities		497,350		(175,658)
Net increase (decrease) in cash and cash equivalents		444,098		(236,419)
Cash and cash equivalents at beginning of period		79,588		359,072
Cash and cash equivalents at end of period		523,686		122,653
Supplemental disclosures
Accretion expense and revisions to the Deferred purchase price obligation – Anadarko		0		(4,094)
Interest paid, net of capitalized interest		28,857		29,014
Taxes paid (reimbursements received)		(87)		189
Accrued capital expenditures		229,484		85,280
Fair value of properties and equipment from non-cash third party transactions	[6]	0		548,628
Chipeta [Member]
Cash flows from financing activities
Distributions to Chipeta noncontrolling interest owner		(3,353)		(3,370)
Western Gas Partners, LP [Member]
Cash flows from financing activities
Proceeds from the issuance of WES common units, net of offering expenses		0		(158)
Distributions to noncontrolling interest owners of WES		(94,272)		(84,172)
Affiliates [Member]
Cash flows from investing activities
Contributions in aid of construction costs from affiliates		0		1,310
Cash flows from financing activities
Distributions to WGP unitholders	[7]	(98,000)		(82,597)
Affiliates [Member] | Western Gas Partners, LP [Member]
Cash flows from financing activities
Distributions to WGP unitholders	[8]	(1,850)		(1,730)
Third Parties [Member]
Cash flows from investing activities
Acquisitions		0		(155,287)
Proceeds from the sale of assets		$ 116		$ 34

[1] Represents amounts earned or incurred on and subsequent to the date of the 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 three months ended March 31, 2017. See Note 1.

[3] Includes losses related to an incident at the DBM complex for the three months ended March 31, 2017. See Note 1.

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

[5] See Note 6.

[6] See Note 3.

[7] Represents distributions paid under WGP’s partnership agreement (see Note 4 and Note 5).

[8] Represents distributions paid to other subsidiaries of Anadarko under WES’s partnership agreement (see Note 4 and Note 5).