Acquisitions - Purchase Price Allocation Table (details) (Western Gas Partners [Member], Anadarko-Operated Marcellus Interest [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Western Gas Partners [Member] \| Anadarko-Operated Marcellus Interest [Member]
Business Acquisition [Line Items]
Property, plant and equipment	$ 134,819
Asset retirement obligations	(174)
Total purchase price	$ 134,645

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Amount of liabilities assumed at the acquisition date.

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Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

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-Name Accounting Standards Codification

-Topic 805

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The amount of property, plant, and equipment recognized as of the acquisition date.

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