Property, Plant and Equipment Table (details) (USD $) In Thousands, unless otherwise specified								9 Months Ended				9 Months Ended						9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012		Sep. 30, 2013 Land [Member] Western Gas Partners [Member]	Dec. 31, 2012 Land [Member] Western Gas Partners [Member]	Sep. 30, 2013 Gas Gathering and Processing Equipment [Member] Western Gas Partners [Member]	Dec. 31, 2012 Gas Gathering and Processing Equipment [Member] Western Gas Partners [Member]	Sep. 30, 2013 Gas Gathering and Processing Equipment [Member] Minimum [Member] Western Gas Partners [Member]	Sep. 30, 2013 Gas Gathering and Processing Equipment [Member] Maximum [Member] Western Gas Partners [Member]	Sep. 30, 2013 Pipelines And Equipment [Member] Western Gas Partners [Member]	Dec. 31, 2012 Pipelines And Equipment [Member] Western Gas Partners [Member]	Sep. 30, 2013 Pipelines And Equipment [Member] Minimum [Member] Western Gas Partners [Member]	Sep. 30, 2013 Pipelines And Equipment [Member] Maximum [Member] Western Gas Partners [Member]	Sep. 30, 2013 Asset under Construction [Member] Western Gas Partners [Member]	Dec. 31, 2012 Asset under Construction [Member] Western Gas Partners [Member]	Sep. 30, 2013 Other [Member] Western Gas Partners [Member]	Dec. 31, 2012 Other [Member] Western Gas Partners [Member]	Sep. 30, 2013 Other [Member] Minimum [Member] Western Gas Partners [Member]	Sep. 30, 2013 Other [Member] Maximum [Member] Western Gas Partners [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 4,061,389	$ 3,432,392	[1]	$ 2,584	$ 501	$ 3,610,879	$ 2,911,572			$ 119,278	$ 91,126			$ 318,107	$ 422,002	$ 10,541	$ 7,191
Accumulated depreciation	817,489	714,436	[1]
Net property, plant and equipment	$ 3,243,900	$ 2,717,956	[1]
Estimated useful life								3 years	47 years			15 years	45 years					3 years	25 years

[1] Financial information has been recast to include the financial position and results attributable to the Non-Operated Marcellus Interest. See Note 2.