Acquisitions and Divestitures - Acquisitions Table (Details) - USD ($) $ in Thousands					3 Months Ended	9 Months Ended
		Mar. 14, 2016	Mar. 02, 2015		Mar. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Deferred purchase price obligation - Anadarko, present value	[1]					$ 16,425		$ 188,674	[2]
Revolving Credit Facility [Member] | WGP RCF [Member]
Business Acquisition [Line Items]
Borrowings		$ 25,000			$ 28,000	$ 28,000
Western Gas Partners, LP [Member]
Business Acquisition [Line Items]
Units issued						748,562
Western Gas Partners, LP [Member] | Revolving Credit Facility [Member] | WES RCF [Member]
Business Acquisition [Line Items]
Borrowings						$ 600,000
Western Gas Partners, LP [Member] | Delaware Basin JV Gathering LLC [Member]
Business Acquisition [Line Items]
Percentage acquired	[3]		100.00%
Western Gas Partners, LP [Member] | Delaware Basin JV Gathering LLC [Member] | Delaware Basin JV Gathering System [Member]
Business Acquisition [Line Items]
Percentage acquired			50.00%
Western Gas Partners, LP [Member] | Delaware Basin JV Gathering LLC [Member] | Deferred Purchase Price Obligation - Anadarko [Member]
Business Acquisition [Line Items]
Deferred purchase price obligation - Anadarko, present value			$ 174,276	[3]	193,211	16,425	$ 29,150	188,674
Deferred purchase price obligation - Anadarko, future value			$ 282,807		$ 282,807	$ 22,920	$ 41,666	$ 282,807
Western Gas Partners, LP [Member] | Springfield Pipeline LLC [Member]
Business Acquisition [Line Items]
Percentage acquired	[4]	100.00%
Acquisition price		$ 750,000
Cash payment for acquisition		$ 712,500
Western Gas Partners, LP [Member] | Springfield Pipeline LLC [Member] | Common Units [Member]
Business Acquisition [Line Items]
Units issued	[4]	2,089,602
Western Gas Partners, LP [Member] | Springfield Pipeline LLC [Member] | Common Units [Member] | Anadarko [Member]
Business Acquisition [Line Items]
Units issued		1,253,761
Western Gas Partners, LP [Member] | Springfield Pipeline LLC [Member] | Common Units [Member] | Western Gas Equity Partners, LP [Member]
Business Acquisition [Line Items]
Units issued		835,841
Western Gas Partners, LP [Member] | Springfield Pipeline LLC [Member] | Series A Preferred Units [Member]
Business Acquisition [Line Items]
Units issued	[4]	14,030,611
Western Gas Partners, LP [Member] | Springfield Pipeline LLC [Member] | Springfield System [Member]
Business Acquisition [Line Items]
Percentage acquired		50.10%
Western Gas Partners, LP [Member] | Springfield Pipeline LLC [Member] | Revolving Credit Facility [Member] | WES RCF [Member]
Business Acquisition [Line Items]
Borrowings	[4]	$ 247,500

[1] See Note 2.

[2] Financial information has been recast to include the financial position and results attributable to the Springfield interest. 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. The DBJV gathering system and related facilities (the “DBJV system”) 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. At the acquisition date, WES estimated the future payment would be $282.8 million, the net present value of which was $174.3 million. For further information, including revisions to the estimated future payment, see DBJV acquisition—deferred purchase price obligation - Anadarko below.

[4] WES acquired Springfield Pipeline LLC (“Springfield”) from Anadarko for $750.0 million, consisting of $712.5 million in cash and the issuance of 1,253,761 of WES common units. Springfield owns a 50.1% interest in an oil gathering system and a gas gathering system, such interest being referred to in this report as the “Springfield interest.” The Springfield oil and gas gathering systems (collectively, the “Springfield system”) are located in Dimmit, La Salle, Maverick and Webb Counties in South Texas. WES financed the cash portion of the acquisition through: (i) borrowings of $247.5 million on the WES RCF, (ii) the issuance of 835,841 of WES common units to WGP and (iii) the issuance of WES Series A Preferred units to private investors. See Note 4 for further information regarding WES’s Series A Preferred units. WGP financed the purchase of the WES common units by borrowing $25.0 million on the WGP RCF. See Note 9.