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

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Acquisitions (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Aug. 01, 2013 Mid-America Midstream Gas Services, LLC [Member]	Dec. 31, 2013 SemGas [Member]	Dec. 31, 2012 SemGas [Member]	Aug. 01, 2013 SemGas [Member] Mid-America Midstream Gas Services, LLC [Member]
Business Acquisition [Line Items]
Property, plant, and equipment acquired					$ 123,316
Customer contract intangible asset acquired					166,332
Goodwill acquired	62,021	9,884	9,453	107,823		23,839	0	23,839
Total assets acquired					$ 313,487