Equity Method Investments (Details Textual) - USD ($) $ in Millions		9 Months Ended
Dec. 22, 2017	Sep. 30, 2018
White Cliffs Pipeline, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of limited partner ownership interest		51.00%
Partners' Capital Account, Contributions		$ 6.5
Remaining expected capital contributions year one		$ 27.2
Glass Mountain Pipeline LLC [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from sale of common units of equity method investee	$ 300.0
NGL Energy Partners LP [Member] \| General Partner [Member]
Schedule of Equity Method Investments [Line Items]
General partner ownership interest		11.78%

Remaining expected capital contributions, year one

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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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-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
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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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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 3
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Total contributions made by each class of partners (i.e., general, limited and preferred partners).

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-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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