Transactions with Affiliates - Summary of Affiliate Transactions Table (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Revenues and other		$ 1,804,270	$ 1,752,072	$ 1,533,377
Equity income, net – affiliates	[1]	78,717	71,251	57,836
Cost of product	[2]	494,194	528,369	458,379
Operation and maintenance	[2]	308,010	331,972	293,710
General and administrative	[2]	49,248	44,428	41,777
Operating expenses		1,180,081	1,726,165	1,039,723
Interest income	[3]	16,900	16,900	16,900
Interest expense	[4]	116,628	113,874	76,769
Distributions to unitholders	[5]	374,082	306,477	228,481
Above-market component of swap extensions with Anadarko	[5]	45,820	18,449	0
Affiliates [Member]
Related Party Transaction [Line Items]
Revenues and other	[1]	1,228,232	1,220,639	1,203,974
Cost of product	[1]	80,455	167,354	127,930
Operation and maintenance	[6]	72,330	77,061	71,386
General and administrative	[7]	38,873	34,703	32,055
Operating expenses		191,658	279,118	231,371
Interest expense	[8]	(7,747)	14,400	3
Affiliates [Member] | Western Gas Partners, LP [Member]
Related Party Transaction [Line Items]
Distributions to unitholders	[9]	5,614	2,235	1,747
Affiliates [Member] | Western Gas Equity Partners, LP [Member]
Related Party Transaction [Line Items]
Distributions to unitholders	[10]	$ 315,505	$ 269,029	$ 204,615

[1] Represents amounts earned or incurred on and subsequent to the date of acquisition of WES assets, as well as amounts earned or incurred by Anadarko on a historical basis related to WES assets prior to the acquisition of such assets by WES, recognized under gathering, treating or processing agreements, and purchase and sale agreements.

[2] Cost of product includes product purchases from Anadarko (as defined in Note 1) of $80.5 million, $167.4 million and $127.9 million for the years ended December 31, 2016, 2015 and 2014, respectively. Operation and maintenance includes charges from Anadarko of $72.3 million, $77.1 million and $71.4 million for the years ended December 31, 2016, 2015 and 2014, respectively. General and administrative includes charges from Anadarko of $38.9 million, $34.7 million and $32.1 million for the years ended December 31, 2016, 2015 and 2014, respectively. See Note 5.

[3] Represents interest income recognized on the note receivable from Anadarko.

[4] Includes affiliate (as defined in Note 1) amounts of $7.7 million, $(14.4) million and zero for the years ended December 31, 2016, 2015 and 2014, respectively. See Note 2 and Note 12.

[5] See Note 5.

[6] Represents expenses incurred on and subsequent to the date of the acquisition of WES assets, as well as expenses incurred by Anadarko on a historical basis related to WES assets prior to the acquisition of such assets by WES.

[7] Represents general and administrative expense incurred on and subsequent to the date of WES’s acquisition of WES assets, as well as a management services fee for reimbursement of expenses incurred by Anadarko for periods prior to the acquisition of WES assets by WES. These amounts include equity-based compensation expense allocated to WES and WGP by Anadarko (see WES LTIP and WGP LTIP and Anadarko Incentive Plans within this Note 5) and amounts charged by Anadarko under the WGP and WES omnibus agreements.

[8] For the years ended December 31, 2016 and 2015, includes amounts related to WES’s Deferred purchase price obligation - Anadarko (see Note 2 and Note 12) and for the years ended December 31, 2015 and 2014, includes interest expense recognized on the WGP WCF (see Note 12).

[9] Represents distributions paid to other subsidiaries of Anadarko under WES’s partnership agreement (see Note 3 and Note 4).

[10] Represents distributions paid under WGP’s partnership agreement (see Note 3 and Note 4).