Description of Business and Basis of Presentation - Additional Information (Details) - USD ($)		3 Months Ended		6 Months Ended				12 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018		Jun. 30, 2017		Dec. 31, 2017	Jan. 01, 2018	May 31, 2008
Note receivable - Anadarko		$ 260,000,000		$ 260,000,000				$ 260,000,000
Revenues and other		435,949,000	$ 525,450,000	873,117,000		$ 1,041,643,000
Impairments		127,243,000	3,178,000	127,391,000		167,920,000		$ 178,400,000
Loss on divestiture and other, net	[1]	(170,000)	(15,458,000)	(286,000)	[2]	(134,945,000)	[2]
Proceeds from property insurance claims				0		22,977,000
Cumulative effect of accounting change	[3]	(44,379,000)		(44,379,000)
Accounting Standards Update 2014-09 [Member]
Cumulative effect of accounting change									$ (44,379,000)
Product Sales [Member]
Revenues and other		$ 54,077,000		$ 130,014,000
Chipeta [Member]
Ownership interest by noncontrolling interest owner		25.00%		25.00%
Affiliates [Member]
Revenues and other	[4]	$ 238,029,000	316,313,000	$ 479,091,000		631,468,000
Affiliates [Member] | Product Sales [Member]
Revenues and other		$ 45,256,000	$ 161,329,000	$ 100,075,000		304,170,000
Western Gas Equity Partners, LP [Member] | Western Gas Partners, LP [Member] | General Partner [Member]
Percentage ownership interest				100.00%
Western Gas Partners, LP [Member] | Minimum [Member]
Contract term		5 years		5 years
Western Gas Partners, LP [Member] | Maximum [Member]
Contract term		10 years		10 years
Western Gas Partners, LP [Member] | Kitty Draw and Third Creek Gathering Systems [Member]
Impairments				$ 127,200,000
Western Gas Partners, LP [Member] | Delaware Basin Midstream Complex [Member]
Loss on divestiture and other, net						5,700,000
Proceeds from insurance claims, total						52,900,000
Proceeds from business interruption insurance claims						29,882,000
Proceeds from property insurance claims						$ 22,977,000
Western Gas Partners, LP [Member] | Affiliates [Member]
Note receivable - Anadarko		$ 260,000,000		260,000,000						$ 260,000,000
Western Gas Partners, LP [Member] | Affiliates [Member] | Product Sales [Member] | Kitty Draw and Third Creek Gathering Systems [Member]
Revenues and other				$ (10,900,000)
Western Gas Partners, LP [Member] | Other Subsidiaries of Anadarko [Member]
WES common units issued				2,011,380

[1] Includes losses related to an incident at the DBM complex for the six months ended June 30, 2017. See Note 1.

[2] Includes losses related to an incident at the DBM complex for the six months ended June 30, 2017. See Note 1.

[3] See Note 1.

[4] 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.