Partnership Distributions - Cash Distributions Table (details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Sep. 30, 2013		Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2013 Western Gas Partners [Member]		Jun. 30, 2013 Western Gas Partners [Member]	Mar. 31, 2013 Western Gas Partners [Member]	Sep. 30, 2012 Western Gas Partners [Member]	Jun. 30, 2012 Western Gas Partners [Member]	Mar. 31, 2012 Western Gas Partners [Member]
Dividends Payable [Line Items]
Total quarterly distribution per unit	$ 0.21375	[1]	$ 0.19750	$ 0.17875	$ 0.03587	$ 0.580	[2]	$ 0.560	$ 0.540	$ 0.500	$ 0.480	$ 0.460
Total quarterly cash distribution	$ 46,789	[1]	$ 43,232	$ 39,128	$ 7,852	$ 83,986	[2]	$ 79,315	$ 70,143	$ 56,346	$ 52,425	$ 46,053

[1] On October 16, 2013, the board of directors of WGP GP declared a cash distribution to WGP unitholders of $0.21375 per unit, or $46.8 million in aggregate. The cash distribution is payable on November 21, 2013, to WGP unitholders of record at the close of business on October 31, 2013.

[2] On October 16, 2013, the board of directors of WES GP declared a cash distribution to WES unitholders of $0.58 per unit, or $84.0 million in aggregate, including incentive distributions. The cash distribution is payable on November 12, 2013, to WES unitholders of record at the close of business on October 31, 2013.