Description of Business and Basis of Presentation - Equity Investments Table (details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Schedule of Equity Method Investments [Line Items]
Balance					$ 593,400	[1]
Investment earnings (loss), net of amortization	19,063	[2],[3]	4,520	[1],[2],[3]	41,322	[2],[3],[4]	11,944	[1],[2],[3],[4]
Contributions					63,267		252,308	[1]
Capitalized interest					857
Distributions					(43,061)	[4]	(15,563)	[1],[4]
Distributions in excess of cumulative earnings					(14,387)	[4],[5]	0	[1],[4]
Balance	639,191				639,191
Equity Investments [Member]
Schedule of Equity Method Investments [Line Items]
Contributions					61,060
Western Gas Partners [Member] | Fort Union [Member]
Schedule of Equity Method Investments [Line Items]
Balance					25,172
Investment earnings (loss), net of amortization					4,811
Contributions					0
Capitalized interest					0
Distributions					(4,619)
Distributions in excess of cumulative earnings					0	[5]
Balance	25,364				25,364
Western Gas Partners [Member] | White Cliffs [Member]
Schedule of Equity Method Investments [Line Items]
Balance					35,039
Investment earnings (loss), net of amortization					8,385
Contributions					10,456
Capitalized interest					0
Distributions					(7,949)
Distributions in excess of cumulative earnings					(891)	[5]
Balance	45,040				45,040
Western Gas Partners [Member] | Rendezvous [Member]
Schedule of Equity Method Investments [Line Items]
Balance					60,928
Investment earnings (loss), net of amortization					1,180
Contributions					0
Capitalized interest					0
Distributions					(2,636)
Distributions in excess of cumulative earnings					(1,993)	[5]
Balance	57,479				57,479
Western Gas Partners [Member] | Mont Belvieu Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Balance					122,480
Investment earnings (loss), net of amortization					22,872
Contributions					3,956
Capitalized interest					0
Distributions					(24,423)
Distributions in excess of cumulative earnings					0	[5]
Balance	124,885				124,885
Western Gas Partners [Member] | Texas Express Gathering Limited Liability Company [Member]
Schedule of Equity Method Investments [Line Items]
Balance					16,649
Investment earnings (loss), net of amortization					466
Contributions					352
Capitalized interest					0
Distributions					(373)
Distributions in excess of cumulative earnings					(338)	[5]
Balance	16,756				16,756
Western Gas Partners [Member] | Texas Express Pipeline Limited Liability Company [Member]
Schedule of Equity Method Investments [Line Items]
Balance					197,731
Investment earnings (loss), net of amortization					3,488
Contributions					6,263
Capitalized interest					0
Distributions					(2,938)
Distributions in excess of cumulative earnings					(5,321)	[5]
Balance	199,223				199,223
Western Gas Partners [Member] | Front Range Pipeline Limited Liability Company [Member]
Schedule of Equity Method Investments [Line Items]
Balance					135,401
Investment earnings (loss), net of amortization					120
Contributions					40,033
Capitalized interest					857
Distributions					(123)
Distributions in excess of cumulative earnings					(5,844)	[5]
Balance	$ 170,444				$ 170,444

[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] 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.

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

[5] Distributions in excess of cumulative earnings, classified as investing cash flows in the consolidated statements of cash flows, is calculated on an individual investment basis.