Transactions With Affiliates - Summary Table (details) (USD $) In Thousands, unless otherwise specified	3 Months Ended						6 Months Ended
	Jun. 30, 2014		Mar. 31, 2014	Jun. 30, 2013		Mar. 31, 2013	Jun. 30, 2014		Jun. 30, 2013
Related Party Transaction [Line Items]
Revenues	$ 329,944			$ 251,402	[1]		$ 609,401		$ 477,168	[1]
Equity income, net	13,008	[2]		3,456	[1],[2]		22,259	[2],[3]	7,424	[1],[2],[3]
Cost of product	118,085	[4]		93,460	[1],[4]		210,035	[4]	176,543	[1],[4]
Operation and maintenance	50,875	[4]		41,669	[1],[4]		91,407	[4]	78,408	[1],[4]
General and administrative	8,757	[4]		8,209	[1],[4]		18,143	[4]	17,138	[1],[4]
Operating expenses	228,576			185,920	[1]		418,097		352,896	[1]
Interest income, net	4,225	[5]		4,225	[1],[5]		8,450	[5]	8,450	[1],[5]
Distributions to unitholders	59,378	[6]	54,726	43,232		39,128
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Revenues	256,666	[7]		200,316	[1],[7]		462,956	[7]	377,885	[1],[7]
Cost of product	35,230	[7]		32,119	[7]		51,864	[7]	64,048	[7]
Operation and maintenance	16,817	[8]		14,186	[8]		27,916	[8]	27,552	[8]
General and administrative	6,644	[9]		5,803	[9]		13,637	[9]	11,891	[9]
Operating expenses	58,691			52,108			93,417		103,491
Affiliated Entity [Member] | Western Gas Equity Partners [Member]
Related Party Transaction [Line Items]
Distributions to unitholders	49,784	[10]		35,596	[10]		95,835	[10]	42,739	[10]
Western Gas Partners [Member]
Related Party Transaction [Line Items]
Distributions to unitholders	105,655	[11]	98,749	79,315		70,143
Western Gas Partners [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Distributions to unitholders	$ 474	[12]		$ 243	[12]		$ 743	[12]	$ 243	[10]

[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] 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] Cost of product includes product purchases from Anadarko (as defined in Note 1) of $35.2 million and $51.9 million for the three and six months ended June 30, 2014, respectively, and $32.1 million and $64.0 million for the three and six months ended June 30, 2013, respectively. Operation and maintenance includes charges from Anadarko of $16.8 million and $27.9 million for the three and six months ended June 30, 2014, respectively, and $14.2 million and $27.6 million for the three and six months ended June 30, 2013, respectively. General and administrative includes charges from Anadarko of $6.6 million and $13.6 million for the three and six months ended June 30, 2014, respectively, and $5.8 million and $11.9 million for the three and six months ended June 30, 2013, respectively. See Note 5.

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

[6] On July 18, 2014, the board of directors of WGP GP declared a cash distribution to WGP unitholders of $0.27125 per unit, or $59.4 million in aggregate. The cash distribution is payable on August 22, 2014, to WGP unitholders of record at the close of business on July 31, 2014.

[7] Represents amounts earned on and subsequent to the date of acquisition of WES assets, as well as amounts earned 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.

[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 July 18, 2014, the board of directors of WES GP declared a cash distribution to WES unitholders of $0.650 per unit, or $105.7 million in aggregate, including incentive distributions. The cash distribution is payable on August 13, 2014, to WES unitholders of record at the close of business on July 31, 2014.

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