Partnership Distributions - Incentive Distribution Rights Table (details) (USD $)	1 Months Ended	3 Months Ended
	May 31, 2008	Dec. 31, 2014		Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total quarterly distribution per unit		$ 0.31250	[1]	$ 0.29125	$ 0.27125	$ 0.25000	$ 0.23125	$ 0.21375	$ 0.19750	$ 0.17875	$ 0.03587
Marginal percentage interest in distributions		1.90%
Western Gas Partners [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total quarterly distribution per unit	$ 0.300	$ 0.700	[2]	$ 0.675	$ 0.650	$ 0.625	$ 0.600	$ 0.580	$ 0.560	$ 0.540	$ 0.520	$ 0.500	$ 0.480	$ 0.460
Western Gas Partners [Member] | Unitholders [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal percentage interest in distributions	98.10%
Western Gas Partners [Member] | Unitholders [Member] | First Target [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal percentage interest in distributions	98.10%
Western Gas Partners [Member] | Unitholders [Member] | Second Target [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal percentage interest in distributions	85.10%
Western Gas Partners [Member] | Unitholders [Member] | Third Target [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal percentage interest in distributions	75.10%
Western Gas Partners [Member] | Unitholders [Member] | Thereafter [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal percentage interest in distributions	50.10%
Western Gas Partners [Member] | General Partner [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal percentage interest in distributions	1.90%
Western Gas Partners [Member] | General Partner [Member] | First Target [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal percentage interest in distributions	1.90%
Western Gas Partners [Member] | General Partner [Member] | Second Target [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal percentage interest in distributions	14.90%
Western Gas Partners [Member] | General Partner [Member] | Third Target [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal percentage interest in distributions	24.90%
Western Gas Partners [Member] | General Partner [Member] | Thereafter [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal percentage interest in distributions	49.90%
Western Gas Partners [Member] | Minimum [Member] | First Target [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total quarterly distribution per unit	$ 0.300
Western Gas Partners [Member] | Minimum [Member] | Second Target [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total quarterly distribution per unit	$ 0.345
Western Gas Partners [Member] | Minimum [Member] | Third Target [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total quarterly distribution per unit	$ 0.375
Western Gas Partners [Member] | Maximum [Member] | First Target [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total quarterly distribution per unit	$ 0.345
Western Gas Partners [Member] | Maximum [Member] | Second Target [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total quarterly distribution per unit	$ 0.375
Western Gas Partners [Member] | Maximum [Member] | Third Target [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total quarterly distribution per unit	$ 0.450
Western Gas Partners [Member] | Maximum [Member] | Thereafter [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total quarterly distribution per unit	$ 0.450

[1] On January 22, 2015, the Board of Directors of WGP GP declared a cash distribution to WGP unitholders of $0.31250 per unit, or $68.4 million in aggregate. The cash distribution was paid on February 20, 2015, to WGP unitholders of record at the close of business on February 2, 2015.

[2] On January 22, 2015, the Board of Directors of WES GP declared a cash distribution to WES unitholders of $0.700 per unit, or $126.0 million in aggregate, including incentive distributions, but excluding distributions on WES Class C units (see WES Class C unit distributions below). The cash distribution was paid on February 12, 2015, to WES unitholders of record at the close of business on February 2, 2015.