Consolidated Statements of Cash Flows - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2018		Sep. 30, 2017
Cash flows from operating activities
Net income (loss)		$ 339,728		$ 423,615
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization		238,187		216,272
Impairments		152,708		170,079
Non-cash equity-based compensation expense		4,834		3,751
Deferred income taxes		3,054		3,882
Accretion and amortization of long-term obligations, net		4,659		3,701
Equity income, net – affiliates	[1]	(102,752)		(62,708)
Distributions from equity investment earnings – affiliates		93,827		64,313
(Gain) loss on divestiture and other, net	[2],[3]	(351)		(135,017)
Lower of cost or market inventory adjustments		184		140
Changes in assets and liabilities:
(Increase) decrease in accounts receivable, net		(64,690)		(47,137)
Increase (decrease) in accounts and imbalance payables and accrued liabilities, net		55,480		4,127
Change in other items, net		24,511		(2,549)
Net cash provided by operating activities		749,379		642,469
Cash flows from investing activities
Capital expenditures		(949,022)		(419,193)
Investments in equity affiliates		(67,979)		(384)
Distributions from equity investments in excess of cumulative earnings – affiliates		18,097	[4]	16,255
Proceeds from property insurance claims		0		22,977
Net cash used in investing activities		(1,160,684)		(514,797)
Cash flows from financing activities
Borrowings, net of debt issuance costs		2,135,629		249,989
Repayments of debt		(1,040,000)		0
Increase (decrease) in outstanding checks		(2,687)		3,310
Distributions to WGP unitholders	[5]	(372,189)		(324,290)
Net contributions from (distributions to) Anadarko		0		30
Above-market component of swap agreements with Anadarko	[5]	40,722		46,719
Net cash provided by (used in) financing activities		464,594		(333,708)
Net increase (decrease) in cash and cash equivalents		53,289		(206,036)
Cash and cash equivalents at beginning of period		79,588		359,072
Cash and cash equivalents at end of period		132,877		153,036
Supplemental disclosures
Accretion expense and revisions to the Deferred purchase price obligation – Anadarko		0		(4,094)
Net distributions to (contributions from) Anadarko of other assets		0		(1,373)
Interest paid, net of capitalized interest		114,790		98,956
Taxes paid (reimbursements received)		(87)		189
Accrued capital expenditures		178,694		165,732
Fair value of properties and equipment from non-cash third party transactions	[6]	0		551,453
Chipeta [Member]
Cash flows from financing activities
Distributions to Chipeta noncontrolling interest owner		(9,446)		(9,049)
Western Gas Partners, LP [Member]
Cash flows from financing activities
Proceeds from the issuance of WES common units, net of offering expenses		0		(183)
Distributions to noncontrolling interest owners of WES		(287,435)		(262,888)
Affiliates [Member]
Cash flows from investing activities
Contributions in aid of construction costs from affiliates		0		1,386
Acquisitions		(254)		(3,910)
Cash flows from financing activities
Settlement of the Deferred purchase price obligation - Anadarko	[6]	0		(37,346)
Distributions to WGP unitholders	[7]	(298,818)		(264,533)
Affiliates [Member] | Western Gas Partners, LP [Member]
Cash flows from financing activities
Distributions to WGP unitholders	[8]	(5,642)		(5,280)
Supplemental disclosures
Net distributions to (contributions from) Anadarko of other assets		0		(1,373)
Third Parties [Member]
Cash flows from investing activities
Acquisitions		(161,858)		(155,298)
Proceeds from the sale of assets		$ 332		$ 23,370

[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 nine months ended September 30, 2017. See Note 1.

[3] Includes losses related to an incident at the DBM complex for the nine months ended September 30, 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).