Equity Method Investments (Details Textual) $ / shares in Units, bbl in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($) $ / shares shares	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) bbl $ / shares shares	Jun. 30, 2014 USD ($)	Mar. 31, 2015 shares
Schedule of Equity Method Investments [Line Items]
Gain on issuance of common units by equity method investee	$ 5,897	$ 0	$ 5,897	$ 8,127
General and administrative	22,917	21,850	55,227	40,586
Net proceeds from sale of common units of equity method investee			56,318	0
Gain on sale of common units of equity method investee			14,517	0
White Cliffs Pipeline, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
General and administrative	400	$ 400	700	800
NGL Energy Partners LP [Member]
Schedule of Equity Method Investments [Line Items]
Common units representing limited partner interests | shares					103,794,870
NGL Energy Partners LP [Member]
Schedule of Equity Method Investments [Line Items]
Gain on issuance of common units by equity method investee	$ 5,900		$ 5,900	$ 8,100
Common units | shares	4,652,568		4,652,568
Fair market value of common units	$ 141,100		$ 141,100
Closing price per common unit | $ / shares	$ 30.33		$ 30.33
Units of equity investee divested | shares	1,999,533
Net proceeds from sale of common units of equity method investee	$ 56,300
NGL Energy Partners LP [Member] | Limited Partner Interests [Member]
Schedule of Equity Method Investments [Line Items]
Limited partner ownership interest			4.50%
NGL Energy Partners LP [Member] | General Partner [Member]
Schedule of Equity Method Investments [Line Items]
General partner ownership interest			11.78%
White Cliffs Pipeline, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Project funding contributions			$ 21,400
Percentage of limited partner ownership interest	51.00%		51.00%
Glass Mountain Pipeline LLC [Member]
Schedule of Equity Method Investments [Line Items]
Project funding contributions			$ 1,400
Percentage of limited partner ownership interest	50.00%		50.00%
Pipeline expansion [Member] | White Cliffs Pipeline, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Project funding contributions			$ 13,100
Incremental capacity expected to be added | bbl			65
Expected capital contributions, year one			$ 23,600
Other Expense [Member] | NGL Energy Partners LP [Member]
Schedule of Equity Method Investments [Line Items]
Transaction related costs	$ 500
Gain on sale of common units of equity method investee	$ 6,600		$ 14,500