Investments in Non-Consolidated Subsidiaries (Details Textual) (USD $)	3 Months Ended							3 Months Ended		3 Months Ended	23 Months Ended		3 Months Ended	20 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 White Cliffs Pipeline, L.L.C. [Member]	Mar. 31, 2013 White Cliffs Pipeline, L.L.C. [Member]	Mar. 31, 2014 General Partner [Member] NGL Energy Partners LP [Member]	Mar. 31, 2014 NGL Energy Partners LP [Member]	Dec. 31, 2013 NGL Energy Partners LP [Member]	Mar. 31, 2014 NGL Energy Partners LP [Member] Limited Partner Interests [Member]	Mar. 31, 2014 White Cliffs Pipeline, L.L.C. [Member] Semcrude Pipeline [Member]	Mar. 31, 2014 Glass Mountain Pipeline LLC [Member]	Mar. 31, 2014 Glass Mountain Pipeline LLC [Member]	Mar. 31, 2014 Pipeline expansion [Member] White Cliffs Pipeline, L.L.C. [Member]	Mar. 31, 2014 Pipeline expansion [Member] White Cliffs Pipeline, L.L.C. [Member] Semcrude Pipeline [Member] Width	Mar. 31, 2014 Pipeline expansion [Member] White Cliffs Pipeline, L.L.C. [Member] Semcrude Pipeline [Member]
Schedule of Equity Method Investments [Line Items]
Gain on issuance of common units by equity method investee	$ 8,127,000	$ 0
Limited partner ownership interest								11.50%
Width of pipeline in inches													12
Total expected project costs												300,000,000
Project funding contributions										11,100,000	143,300,000		12,800,000	110,600,000
General and administrative	18,736,000	17,037,000	400,000	300,000
Common units						9,133,409
Percentage of limited partner ownership interest									51.00%	50.00%	50.00%
Common units representing limited partner interests							79,327,078
General partner ownership interest					11.78%
Fair market value of common units						342,800,000
Closing price per common unit	$ 65.68					$ 37.53
Additional cash capital contribution, year one										$ 6,100,000	$ 6,100,000		$ 40,600,000	$ 40,600,000