Debt and Interest Expense - Interest Expense Table (Details) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014		Sep. 30, 2015	Sep. 30, 2014
Debt Instrument [Line Items]
Interest expense	[1]	$ 31,773	$ 20,878	[2]	$ 82,339	$ 55,703	[2]
Third Parties [Member]
Debt Instrument [Line Items]
Interest expense		27,463	20,878		72,417	55,703
Affiliates [Member]
Debt Instrument [Line Items]
Interest expense	[3]	4,310	0		9,922	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		26,972	21,671		75,047	59,251
Amortization of debt issuance costs and commitment fees		1,530	1,107		4,196	3,799
Capitalized interest		(1,039)	(1,900)		(6,826)	(7,347)
Western Gas Partners, LP [Member] | Affiliates [Member] | Deferred Purchase Price Obligation - Anadarko [Member]
Debt Instrument [Line Items]
Interest expense, related party	[4]	$ 4,310	$ 0		$ 9,920	$ 0

[1] Includes affiliate (as defined in Note 1) interest expense of $4.3 million and $9.9 million for the three and nine months ended September 30, 2015, respectively, and zero for each of the three and nine months ended September 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 nine months ended September 30, 2015, includes WES’s accretion expense recognized on the Deferred purchase price obligation - Anadarko for the acquisition of DBJV (see Note 2 and Note 9) and for the nine months ended September 30, 2015, includes interest expense recognized on the WGP working capital facility (see Note 9).

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