Transactions With Affiliates - Summary Table (details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2015	Mar. 31, 2014
Related Party Transaction [Line Items]
Revenues		$ 388,409	$ 301,249	[1]
Equity income, net	[2],[3],[4]	18,220	9,251	[1]
Cost of product	[5]	139,425	95,391	[1]
Operation and maintenance	[5]	67,959	51,094	[1]
General and administrative	[5]	11,347	9,875	[1]
Operating expenses		561,948	205,679	[1]
Interest income	[6]	4,225	4,225	[1]
Interest expense	[7]	22,962	13,961	[1]
Distributions to unitholders		68,409	50,621	[1]
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Revenues	[4]	258,315	222,116	[1]
Cost of product	[4]	43,912	19,371
Operation and maintenance	[8]	15,376	12,551
General and administrative	[9]	7,766	7,482
Operating expenses		67,054	39,404
Interest expense	[10]	1,422	0
Affiliated Entity [Member] | Western Gas Equity Partners [Member]
Related Party Transaction [Line Items]
Distributions to unitholders	[11]	60,434	46,051
Western Gas Partners [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Distributions to unitholders	[12]	$ 530	$ 269

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

[2] Income earned from equity investments is classified as affiliate. See Note 1.

[3] Income earned on, distributions from and contributions to equity investments are classified as affiliate. See Note 1.

[4] 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. See Adjustments to Previously Issued Financial Statements in Note 1.

[5] Cost of product includes product purchases from Anadarko (as defined in Note 1) of $43.9 million and $19.4 million for the three months ended March 31, 2015 and 2014, respectively. Operation and maintenance includes charges from Anadarko of $15.4 million and $12.6 million for the three months ended March 31, 2015 and 2014, respectively. General and administrative includes charges from Anadarko of $7.8 million, and $7.5 million for the three months ended March 31, 2015 and 2014, respectively. See Note 5.

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

[7] Includes affiliate (as defined in Note 1) interest expense of $1.4 million and zero for the three months ended March 31, 2015 and 2014, respectively. See Note 2 and Note 9.

[8] 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.

[9] 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 omnibus agreement.

[10] For the three months ended March 31, 2015, includes interest expense recognized on the WGP working capital facility (see Note 9) and WES’s accretion expense recognized on the Deferred purchase price obligation - Anadarko for the acquisition of DBJV (see Note 2 and Note 9).

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

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