Debt and Interest Expense - Interest Expense Table (Details) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014		Jun. 30, 2015	Jun. 30, 2014
Debt Instrument [Line Items]
Interest expense	[1]	$ 27,604	$ 20,864	[2]	$ 50,566	$ 34,825	[2]
Third Parties [Member]
Debt Instrument [Line Items]
Interest expense		23,414	20,864		44,954	34,825
Affiliates [Member]
Debt Instrument [Line Items]
Interest expense	[3]	4,190	0		5,612	0
Anadarko [Member] | Working Capital Facility [Member]
Debt Instrument [Line Items]
Interest expense, related party		0	0		2	0
Western Gas Partners, LP [Member] | Third Parties [Member]
Debt Instrument [Line Items]
Long-term debt		24,733	21,445		48,075	37,580
Amortization of debt issuance costs and commitment fees		1,374	1,426		2,666	2,692
Capitalized interest		(2,693)	(2,007)		(5,787)	(5,447)
Western Gas Partners, LP [Member] | Affiliates [Member] | Deferred Purchase Price Obligation - Anadarko [Member]
Debt Instrument [Line Items]
Interest expense, related party	[4]	$ 4,190	$ 0		$ 5,610	$ 0

[1] Includes affiliate (as defined in Note 1) interest expense of $4.2 million and $5.6 million for the three and six months ended June 30, 2015, respectively, and zero for each of the three and six months ended June 30, 2014. See Note 2 and Note 9.

[2] Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.

[3] For the three and six months ended June 30, 2015, includes interest expense recognized on the WGP working capital facility (see Note 9) and WES’s accretion expense recognized on the Deferred purchase price obligation - Anadarko for the acquisition of DBJV (see Note 2 and Note 9).

[4] See Note 2 for a discussion of the accretion and present value of the Deferred purchase price obligation - Anadarko.