Acquisitions and Divestitures - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015		Mar. 02, 2015
Property, Plant and Equipment [Line Items]
Deferred purchase price obligation - Anadarko	[1]	$ 193,211		$ 188,674	[2]
Western Gas Partners, LP [Member] | Delaware Basin JV Gathering LLC [Member] | Deferred Purchase Price Obligation - Anadarko [Member]
Property, Plant and Equipment [Line Items]
Discount rate percentage		10.00%
Deferred purchase price obligation - Anadarko		$ 193,200		$ 188,700
Interest expense, related party		$ 4,500	$ 1,400
Western Gas Partners, LP [Member] | Delaware Basin JV Gathering LLC [Member] | Deferred Purchase Price Obligation - Anadarko [Member] | Level 3 Inputs [Member]
Property, Plant and Equipment [Line Items]
Deferred purchase price obligation to Anadarko - future value						$ 282,800
Deferred purchase price obligation to Anadarko - acquisition date value	[3]					$ 174,276

[1] See Note 2.

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

[3] WES acquired Delaware Basin JV Gathering LLC (“DBJV”) from Anadarko. DBJV owns a 50% interest in a gathering system and related facilities, such interest being referred to in this report as the “DBJV system”. The DBJV gathering system and related facilities are located in the Delaware Basin in Loving, Ward, Winkler and Reeves Counties, Texas. WES will make a cash payment on March 31, 2020, to Anadarko as consideration for the acquisition of DBJV. WES currently estimates the future payment will be $282.8 million, the net present value of which was $174.3 million as of the acquisition date. See DBJV acquisition—deferred purchase price obligation - Anadarko below.