Equity Method Invesments (Summarized Balance Sheet Information) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
White Cliffs Pipeline, LLC [Member]
Current assets	$ 35,623	$ 98,457
Property, plant and equipment, net	471,179	312,831
Goodwill	17,000	17,000
Other intangible assets, net	16,043	20,802
Total assets	539,845	449,090
Current liabilities	11,108	9,648
Members’ equity	528,737	439,442
Total liabilities and members’ equity	539,845	449,090
Glass Mountain Pipeline LLC [Member]
Current assets	8,810
Property, plant and equipment, net	215,876
Total assets	224,686
Current liabilities	2,643
Other liabilities	42
Members’ equity	222,001
Total liabilities and members’ equity	224,686
Ngl Energy Partners Lp [Member]
Current assets	2,585,053	1,013,859
Property, plant and equipment, net	1,433,313	631,663
Goodwill	1,170,490	840,287
Other intangible assets, net	1,362,823	540,684
Total assets	6,551,679	3,026,493
Current liabilities	1,759,980	800,658
Long-term debt	2,437,351	906,066
Other noncurrent liabilities	39,518	2,673
Members’ equity	2,314,830	1,317,096
Total liabilities and members’ equity	$ 6,551,679	$ 3,026,493