Equity Method Investments (Details Textual) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
White Cliffs Pipeline, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	51.00%		51.00%
Proceeds from Equity Method Investment, Dividends or Distributions, Return of and Return on Capital	$ 15.1	$ 18.6	$ 51.5	$ 57.2
Partners' Capital Account, Contributions	$ 5.4	$ 4.7	25.5	$ 6.5
Remaining expected capital contributions year one			$ 3.3
General Partner [Member] \| NGL Energy Partners LP [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	11.78%		11.78%

Proceeds from Equity Method Investment, Dividends or Distributions, Return of and Return on Capital

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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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
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Total contributions made by each class of partners (i.e., general, limited and preferred partners).

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
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