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Commitments and Contingencies - Additional Information (details) (Western Gas Partners [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Loss Contingencies [Line Items]
Committed capital	$ 53.6
Rent expense associated with office and equipment leases	$ 0.8	$ 0.7
Purchase Commitment [Member]
Loss Contingencies [Line Items]
Term of instrument or obligation	12 months

Minimum amount to be expended to satisfy the terms of arrangements in which the entity has agreed to expend funds to procure goods or services, excluding long-term purchase commitments or unconditional purchase obligations.

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