Partnership Distributions - Cash Distributions Tables (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Sep. 30, 2017		Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016
Distribution Made to Limited Partner [Line Items]
Total quarterly distribution per unit	$ 0.53750	[1]	$ 0.52750	$ 0.49125	$ 0.46250	$ 0.44750	$ 0.43375	$ 0.42375
Total quarterly cash distribution	$ 117,677	[1]	$ 115,487	$ 107,549	$ 101,254	$ 97,968	$ 94,958	$ 92,767
Western Gas Partners, LP [Member]
Distribution Made to Limited Partner [Line Items]
Total quarterly distribution per unit	$ 0.905	[2]	$ 0.890	$ 0.875	$ 0.860	$ 0.845	$ 0.830	$ 0.815
Total quarterly cash distribution	$ 212,038	[2]	$ 207,491	$ 188,753	$ 170,657	$ 166,742	$ 162,827	$ 158,905

[1] The Board of Directors declared a cash distribution to WGP unitholders for the third quarter of 2017 of $0.53750 per unit, or $117.7 million in aggregate. The cash distribution is payable on November 22, 2017, to WGP unitholders of record at the close of business on November 2, 2017.

[2] The Board of Directors of WES GP declared a cash distribution to WES unitholders for the third quarter of 2017 of $0.905 per unit, or $212.0 million in aggregate, including incentive distributions, but excluding distributions on WES Class C units (see WES Class C unit distributions below). The cash distribution is payable on November 13, 2017, to WES unitholders of record at the close of business on November 2, 2017.