Transactions With Affiliates - Gains Losses Commodity Price Swap Table (details) (Western Gas Partners [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Gains (losses) on commodity price swap
Net gains (losses) on commodity price swap agreements	$ 5,769		$ 6,831
Cost of Sales [Member]
Gains (losses) on commodity price swap
Net gains (losses) on commodity price swap agreements	(19)	[1]	(19,854)	[1]
Sales [Member]
Gains (losses) on commodity price swap
Net gains (losses) on commodity price swap agreements	5,788	[2]	26,685	[2]
Sales [Member] | Natural Gas, Per Thousand Cubic Feet [Member]
Gains (losses) on commodity price swap
Net gains (losses) on commodity price swap agreements	(3,667)	[2]	5,380	[2]
Sales [Member] | Natural Gas Liquids [Member]
Gains (losses) on commodity price swap
Net gains (losses) on commodity price swap agreements	$ 9,455	[2]	$ 21,305	[2]

[1] Reported in cost of product in the consolidated statements of income in the period in which the related purchase is recorded.

[2] Reported in affiliate natural gas, natural gas liquids and condensate sales in the consolidated statements of income in the period in which the related sale is recorded.