Investments in Unconsolidated Affiliates - Activity Related to Partnership's Investments in Unconsolidated Affiliates (Parenthetical) (Details) $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($)
GCX [Member]
Schedule Of Equity Method Investments [Line Items]
Ownership interest	25.00%
Targa Resources Partners LP [Member] \| T2 Joint Ventures [Member]
Schedule Of Equity Method Investments [Line Items]
Unamortized excess fair value	$ 25.0
Preliminary estimated useful lives of the underlying assets	20 years
GCX DevCo JV [Member]
Schedule Of Equity Method Investments [Line Items]
Ownership interest	20.00%

The estimated periods of time over which underlying assets amortized on a straight-line basis.

No definition available.

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- Definition

Difference between amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee.

+ 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)(3)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

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- Definition

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)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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