Acquisitions and Divestitures - Acquisitions Table (Details) - USD ($) $ in Thousands							1 Months Ended	3 Months Ended		12 Months Ended
		Mar. 14, 2016	Mar. 02, 2015		Nov. 25, 2014	Mar. 03, 2014	Nov. 30, 2014	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Borrowings - long-term debt										$ 1,323,198	$ 889,606	$ 1,648,028
Deferred purchase price obligation - Anadarko, present value	[1]							$ 41,440		41,440	$ 188,674
Revolving Credit Facility [Member] | WGP RCF [Member]
Business Acquisition [Line Items]
Borrowings - revolving credit facility		$ 25,000							$ 28,000	$ 28,000
Western Gas Partners, LP [Member]
Business Acquisition [Line Items]
WES units issued										946,261	498,009
Western Gas Partners, LP [Member] | Revolving Credit Facility [Member] | WES RCF [Member]
Business Acquisition [Line Items]
Borrowings - revolving credit facility										$ 600,000	$ 400,000
Western Gas Partners, LP [Member] | Class C Units [Member]
Business Acquisition [Line Items]
WES units issued								178,977		946,261	498,009
Proceeds from the issuance of WES units							$ 750,000			$ 0	$ 0	750,000
Western Gas Partners, LP [Member] | Series A Preferred Units [Member]
Business Acquisition [Line Items]
Proceeds from the issuance of WES units		$ 440,000								$ 686,937	0	$ 0
Western Gas Partners, LP [Member] | General Partner [Member]
Business Acquisition [Line Items]
Percentage acquired										100.00%
WES units issued	[2],[3]						153,061
Western Gas Partners, LP [Member] | Texas Express And Front Range [Member]
Business Acquisition [Line Items]
Borrowings - long-term debt	[4]					$ 350,000
Cash on hand	[4]					$ 6,250
General partners units issued						6,296
Western Gas Partners, LP [Member] | Texas Express And Front Range [Member] | Common Units [Member]
Business Acquisition [Line Items]
WES common units issued	[4]					308,490
Western Gas Partners, LP [Member] | Texas Express And Front Range [Member] | General Partner [Member]
Business Acquisition [Line Items]
Proceeds from the issuance of WES units						$ 400
Western Gas Partners, LP [Member] | Delaware Basin Midstream LLC [Member]
Business Acquisition [Line Items]
Borrowings - long-term debt	[5]				$ 475,000
Cash on hand	[5]				$ 298,327
Percentage acquired	[5]				100.00%
Western Gas Partners, LP [Member] | Delaware Basin Midstream LLC [Member] | Class C Units [Member]
Business Acquisition [Line Items]
WES units issued	[5]				10,913,853
Western Gas Partners, LP [Member] | Delaware Basin JV Gathering LLC [Member]
Business Acquisition [Line Items]
Percentage acquired	[6]		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	[6]				$ 41,440		$ 41,440	188,674
Deferred purchase price obligation - Anadarko, future value			$ 282,807					$ 56,455		$ 56,455	$ 282,807
Western Gas Partners, LP [Member] | Springfield Pipeline LLC [Member]
Business Acquisition [Line Items]
WES common units issued										16,120,213
Percentage acquired	[7]	100.00%
Acquisition price		$ 750,000
Cash payment for acquisition		$ 712,500
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 - revolving credit facility	[7]	$ 247,500
Western Gas Partners, LP [Member] | Springfield Pipeline LLC [Member] | Common Units [Member]
Business Acquisition [Line Items]
WES common units issued										2,089,602
WES units issued	[7]	2,089,602
Western Gas Partners, LP [Member] | Springfield Pipeline LLC [Member] | Common Units [Member] | Anadarko [Member]
Business Acquisition [Line Items]
WES 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]
WES units issued		835,841
Western Gas Partners, LP [Member] | Springfield Pipeline LLC [Member] | Series A Preferred Units [Member]
Business Acquisition [Line Items]
WES common units issued										14,030,611
WES units issued	[7]	14,030,611
Western Gas Partners, LP [Member] | Texas Express Pipeline LLC [Member]
Business Acquisition [Line Items]
Percentage acquired						20.00%
Western Gas Partners, LP [Member] | Texas Express Gathering LLC [Member]
Business Acquisition [Line Items]
Percentage acquired						20.00%
Western Gas Partners, LP [Member] | Front Range Pipeline LLC [Member]
Business Acquisition [Line Items]
Percentage acquired						33.33%

[1] See Note 2.

[2] Includes the issuance of 1,120,153 WES common units pursuant to the partial exercise of the underwriters’ over-allotment option, the net proceeds from which were $77.0 million. Beginning with this partial exercise, WES GP elected not to make a corresponding capital contribution to maintain its 2.0% interest in WES.

[3] Represents general partner units of WES issued to WES GP in exchange for WES GP’s proportionate capital contribution.

[4] WES acquired a 20% interest in each of TEG and TEP and a 33.33% interest in FRP from Anadarko. These assets gather and transport NGLs primarily from the Anadarko and Denver-Julesburg (“DJ”) Basins. The interests in these entities are accounted for under the equity method of accounting. In connection with the issuance of WES common units, WES issued 6,296 general partner units to WES GP in exchange for WES GP’s proportionate capital contribution of $0.4 million.

[5] WES acquired Nuevo Midstream, LLC (“Nuevo”) from a third party. Following the acquisition, WES changed the name of Nuevo to Delaware Basin Midstream, LLC (“DBM”). The assets acquired include cryogenic processing plants, a gas gathering system, and related facilities and equipment, which are collectively referred to as the “DBM complex” and serve production from Reeves, Loving and Culberson Counties, Texas and Eddy and Lea Counties, New Mexico. See DBM acquisition below for further information, including the final allocation of the purchase price.

[6] 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.

[7] 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 under the WGP RCF. See Note 12.