Debt and Interest Expense - Interest Expense Table (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Debt Instrument [Line Items]
Interest expense	[1]	$ (36,297)	$ (13,429)	$ (72,330)	$ (45,568)
Third Parties [Member]
Debt Instrument [Line Items]
Long-term debt		(35,375)	(28,472)	(70,189)	(56,328)
Amortization of debt issuance costs and commitment fees		(1,982)	(1,900)	(3,946)	(3,495)
Capitalized interest		1,060	1,482	1,876	3,331
Interest expense		(36,297)	(28,890)	(72,259)	(56,492)
Affiliates [Member]
Debt Instrument [Line Items]
Interest expense	[2]	0	15,461	(71)	10,924
Affiliates [Member] | Deferred Purchase Price Obligation - Anadarko [Member]
Debt Instrument [Line Items]
Deferred purchase price obligation - Anadarko	[3]	$ 0	$ 15,461	$ (71)	$ 10,924

[1] Includes affiliate (as defined in Note 1) amounts of zero and $(0.1) million for the three and six months ended June 30, 2017, respectively, and $15.5 million and $10.9 million for the three and six months ended June 30, 2016, respectively. See Note 2 and Note 9.

[2] Includes amounts related to WES’s Deferred purchase price obligation - Anadarko (see Note 2 and Note 9).

[3] See Note 2 for a discussion of the Deferred purchase price obligation - Anadarko.