Partnership Distributions - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended
	Feb. 28, 2019	Mar. 31, 2019		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018
Distribution Made to Limited Partner [Line Items]
Partnership agreement day requirement of distribution of available cash		55 days
Common units outstanding		452,990,862		218,937,797
Total quarterly cash distribution		$ 276,324	[1]	$ 131,910	[2]	$ 130,268	[2]	$ 127,531	[2]	$ 124,518	[2]
WES Operating [Member]
Distribution Made to Limited Partner [Line Items]
Total quarterly cash distribution		$ 283,300		$ 234,787		$ 230,239		$ 225,691		$ 221,133
Distribution sharing percentage	1.50%
Incentive distributions percentage	48.00%
WES Operating [Member] | Common Units [Member]
Distribution Made to Limited Partner [Line Items]
Common units outstanding	152,609,285
WES Operating [Member] | Class C Units [Member]
Distribution Made to Limited Partner [Line Items]
Common units outstanding	14,681,388
Class C units, discount rate percentage on distribution	6.00%
Class C units, common units issued upon conversion	1
WES Operating [Member] | Anadarko [Member] | Common Units [Member]
Distribution Made to Limited Partner [Line Items]
Common units outstanding		6,375,284

[1] The Board of Directors declared a cash distribution to the Partnership’s unitholders for the first quarter of 2019 of $0.61000 per unit, or $276.3 million in aggregate. The cash distribution is payable on May 14, 2019, to unitholders of record at the close of business on May 1, 2019.

[2] The 2018 distributions were declared and paid prior to the closing of the Merger.