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Remaining expected capital contributions, year one

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Transaction related costs

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Units of equity investee divested

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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This item represents the aggregate value of each identified investment accounted for under the equity method of accounting based on the quoted market price for those investments in common stock for which a quoted market price is available.

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Amount of gain (loss) on sale or disposal of an equity method investment.

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The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

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Number of shares of affiliates held for management investment companies.

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Percentage investment held by the managing member or general partner of the limited liability company (LLC) or limited partnership (LP).

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The number of units or percentage investment held by one or more members or limited partners of the LLC or LP.

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The number of limited partner units outstanding.

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Total contributions made by each class of partners (i.e., general, limited and preferred partners).

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The cash inflow associated with the sale of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

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Price of a single share of a number of saleable stocks of a company.

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Equity Method Investments (Details Textual) (USD $)	3 Months Ended
Equity Method Investments (Details Textual) (USD $)	Mar. 31, 2015	Mar. 31, 2014	Jun. 30, 2015	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
General and administrative	$ 32,310,000us-gaap_GeneralAndAdministrativeExpense	$ 18,736,000us-gaap_GeneralAndAdministrativeExpense
Net proceeds from sale of common units of equity method investee	29,012,000	0
Gain on sale of common units of equity method investee	7,894,000	0
White Cliffs Pipeline, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
General and administrative	300,000	400,000
NGL Energy Partners LP [Member]
Schedule of Equity Method Investments [Line Items]
Common units representing limited partner interests				88,545,764
NGL Energy Partners LP [Member]
Schedule of Equity Method Investments [Line Items]
Common units	5,652,568
Fair market value of common units	148,300,000
Closing price per common unit	$ 26.23
Units of equity investee divested	999,533
Net proceeds from sale of common units of equity method investee	29,000,000
NGL Energy Partners LP [Member] \| Limited Partner Interests [Member]
Schedule of Equity Method Investments [Line Items]
Limited partner ownership interest	6.40%
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	14,900,000
Percentage of limited partner ownership interest	51.00%
Glass Mountain Pipeline LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of limited partner ownership interest	50.00%
Pipeline expansion [Member] \| White Cliffs Pipeline, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Project funding contributions	6,600,000
Incremental capacity expected to be added	65,000
Expected capital contributions, year one	30,100,000
Subsequent Event [Member] \| NGL Energy Partners LP [Member]
Schedule of Equity Method Investments [Line Items]
Units of equity investee divested			1,000,000
Net proceeds from sale of common units of equity method investee			27,300,000
Other Expense [Member] \| NGL Energy Partners LP [Member]
Schedule of Equity Method Investments [Line Items]
Transaction related costs	400,000
Gain on sale of common units of equity method investee	7,900,000
Other Expense [Member] \| Subsequent Event [Member] \| NGL Energy Partners LP [Member]
Schedule of Equity Method Investments [Line Items]
Transaction related costs			100,000
Gain on sale of common units of equity method investee			$ 6,600,000