Transactions With Affiliates - Summary Table (details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								9 Months Ended
	Sep. 30, 2014		Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2013		Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2014		Sep. 30, 2013
Related Party Transaction [Line Items]
Revenues	$ 326,465				$ 273,502	[1]			$ 935,866		$ 750,670	[1]
Equity income, net	19,063	[2],[3]			4,520	[1],[2],[3]			41,322	[2],[3],[4]	11,944	[1],[2],[3],[4]
Cost of product	108,393	[5]			93,516	[1],[5]			318,428	[5]	270,059	[1],[5]
Operation and maintenance	53,657	[5]			42,757	[1],[5]			145,064	[5]	121,165	[1],[5]
General and administrative	8,666	[5]			7,962	[1],[5]			26,809	[5]	25,100	[1],[5]
Operating expenses	222,931				188,499	[1]			641,028		541,395	[1]
Interest income, net	4,225	[6]			4,225	[1],[6]			12,675	[6]	12,675	[1],[6]
Distributions to unitholders	63,756	[7]	59,378	54,726	46,789		43,232	39,128
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Revenues	245,500	[2]			213,125	[1],[2]			708,456	[2]	591,010	[1],[2]
Cost of product	22,728	[2]			33,753	[2]			74,592	[2]	97,801	[2]
Operation and maintenance	14,556	[8]			13,469	[8]			42,472	[8]	41,021	[8]
General and administrative	6,765	[9]			6,090	[9]			20,402	[9]	17,981	[9]
Operating expenses	44,049				53,312				137,466		156,803
Affiliated Entity [Member] | Western Gas Equity Partners [Member]
Related Party Transaction [Line Items]
Distributions to unitholders	52,456	[10]			39,329	[10]			148,291	[10]	82,068	[10]
Western Gas Partners [Member]
Related Party Transaction [Line Items]
Distributions to unitholders	111,609	[11]	105,655	98,749	83,986		79,315	70,143
Western Gas Partners [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Distributions to unitholders	$ 492	[12]			$ 252	[12]			$ 1,235	[12]	$ 495	[12]

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

[2] 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.

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

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

[5] Cost of product includes product purchases from Anadarko (as defined in Note 1) of $22.7 million and $74.6 million for the three and nine months ended September 30, 2014, respectively, and $33.8 million and $97.8 million for the three and nine months ended September 30, 2013, respectively. Operation and maintenance includes charges from Anadarko of $14.6 million and $42.5 million for the three and nine months ended September 30, 2014, respectively, and $13.5 million and $41.0 million for the three and nine months ended September 30, 2013, respectively. General and administrative includes charges from Anadarko of $6.8 million and $20.4 million for the three and nine months ended September 30, 2014, respectively, and $6.1 million and $18.0 million for the three and nine months ended September 30, 2013, respectively. See Note 5.

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

[7] On October 20, 2014, the board of directors of WGP GP declared a cash distribution to WGP unitholders of $0.29125 per unit, or $63.8 million in aggregate. The cash distribution is payable on November 21, 2014, to WGP unitholders of record at the close of business on October 31, 2014.

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

[11] On October 20, 2014, the board of directors of WES GP declared a cash distribution to WES unitholders of $0.675 per unit, or $111.6 million in aggregate, including incentive distributions. The cash distribution is payable on November 13, 2014, to WES unitholders of record at the close of business on October 31, 2014.

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