Related Party Transactions - Summary of Transactions with Unconsolidated Affiliates (Details) - Targa Resources Partners LP [Member] - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Revenues	$ 18.1	$ 11.1	$ 5.6
Product purchases	(73.9)	(40.5)	(14.1)
Operating expenses	(19.6)	(3.4)	(3.6)
General and administrative expenses	(0.8)	(0.3)
Gulf Coast Fractionators LP [Member]
Related Party Transaction [Line Items]
Revenues	0.4	0.3	0.3
Product purchases		(7.9)	(5.1)
Operating expenses	(16.0)
T2 Joint Ventures [Member]
Related Party Transaction [Line Items]
Revenues	4.5	3.7	5.2
Product purchases			(0.6)
Operating expenses	(1.2)	(2.0)	(3.6)
Cayenne [Member]
Related Party Transaction [Line Items]
Product purchases	(5.9)	(7.9)	(7.2)
Operating expenses	(0.2)	(0.2)
GCX [Member]
Related Party Transaction [Line Items]
Revenues	0.6	0.8	0.1
Product purchases	(68.0)	(24.7)	$ (1.2)
Little Missouri 4 [Member]
Related Party Transaction [Line Items]
Revenues	12.6	6.3
Operating expenses	(2.2)
General and administrative expenses	$ (0.8)	(0.3)
Agua Blanca [Member]
Related Party Transaction [Line Items]
Operating expenses		$ (1.2)

Related party transaction purchases sale from related party.

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- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

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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.

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- Definition

Amount of selling, general and administrative expenses resulting from transactions, excluding transactions that are eliminated in consolidated or combined financial statements, with related party.

+ References

No definition available.

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- Definition

Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07.1(c))
-URI http://asc.fasb.org/extlink&oid=120401555&loc=SL114874292-224272

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(e))
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

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