Derivatives and Risk Management Activities - Broker Receivable/Payable (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Offsetting Assets, Liabilities [Line Items]
Initial margin	$ 66	$ 53
Variation margin posted	59	49
Letters of credit	(78)	(90)
Net broker receivable	96	72
Exchange Traded
Offsetting Assets, Liabilities [Line Items]
Letters of credit	$ (29)	$ (30)

The amount of cash or securities required by a broker or counterparty as security for a trading or derivatives securities position.

No definition available.

+ Details

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Namespace Prefix:	pagp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
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Period Type:	duration

- Definition

Cash posted by (returned to) the reporting entity to (from) a broker or counterparty to comply with initial margin requirements.

+ References

No definition available.

+ Details

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Namespace Prefix:	pagp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of right to receive cash collateral under master netting arrangements offset against derivative liabilities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-SubTopic 10
-Topic 815
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480463/815-10-45-5

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-SubTopic 20
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483466/210-20-50-3

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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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Namespace Prefix:
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