Transactions With Affiliates - Omnibus Agreement Tables (details) (Omnibus Agreement [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Related Party Transaction [Line Items]
Allocated costs from Anadarko	$ 2,240	$ 2,662	$ 516
General and Administrative Expenses [Member]
Related Party Transaction [Line Items]
Allocated costs from Anadarko	254	271	13
Public Company Expenses [Member]
Related Party Transaction [Line Items]
Allocated costs from Anadarko	1,986	2,391	503
Western Gas Partners [Member]
Related Party Transaction [Line Items]
Allocated costs from Anadarko	28,255	24,034	21,734
Western Gas Partners [Member] | General and Administrative Expenses [Member]
Related Party Transaction [Line Items]
Allocated costs from Anadarko	20,249	16,882	14,904
Western Gas Partners [Member] | Public Company Expenses [Member]
Related Party Transaction [Line Items]
Allocated costs from Anadarko	$ 8,006	$ 7,152	$ 6,830