Acquisitions (Details Textual) (USD $)	0 Months Ended		0 Months Ended	3 Months Ended	6 Months Ended	0 Months Ended	1 Months Ended	6 Months Ended
	Jun. 25, 2014 Sem Crude [Member] Chesapeake crude oil trucking assets [Member]	Jun. 23, 2014 Sem Crude [Member] Chesapeake crude oil trucking assets [Member] Trailers Trucks	Sep. 02, 2013 Sem Crude [Member] Barcas Field Services, LLC [Member]	Mar. 31, 2014 Sem Crude [Member] Barcas Field Services, LLC [Member]	Jun. 30, 2014 Sem Crude [Member] Barcas Field Services, LLC [Member]	Aug. 03, 2013 SemGas [Member] Mid-America Midstream Gas Services, LLC [Member]	Jun. 30, 2014 SemGas [Member] Mid-America Midstream Gas Services, LLC [Member]	Jun. 30, 2014 SemGas [Member] Mid-America Midstream Gas Services, LLC [Member]	Mar. 31, 2014 SemStream [Member] General Partner [Member] NGL Energy Partners LP [Member]	Aug. 06, 2013 SemStream [Member] General Partner [Member] NGL Energy Partners LP [Member] Additional interest acquired [Member]
Business Acquisition [Line Items]
Payments to acquire businesses	$ 44,000,000		$ 49,000,000			$ 313,500,000
Trucks purchased		124
Trailers purchased		122
Goodwill, Purchase Accounting Adjustments				(98,000)	(98,000)		(10,787,000)	(10,787,000)
Finite-Lived Intangible Assets, Purchase Accounting Adjustments							(2,300,000)
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment								$ 500,000
Equity method investment, ownership percentage									11.78%	5.36%