Debt, Number Of Instruments

No definition available.

Name:	pagp_DebtNumberOfInstruments
Namespace Prefix:	pagp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the period for which the credit facility may be extended by the entity, pursuant to the terms of the credit agreement.

+ References

No definition available.

+ Details

Name:	pagp_LineOfCreditFacilityPeriodForWhichTermOfCreditFacilityMayBeExtended
Namespace Prefix:	pagp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of One Year Extensions Provided for Under Agreement

+ References

No definition available.

+ Details

Name:	pagp_NumberOfOneYearExtensionsProvidedForUnderAgreement
Namespace Prefix:	pagp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
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+ Details

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

- 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

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=pagp_SeniorSecuredHedgedInventoryFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShortTermDebtTypeAxis=us-gaap_StandbyLettersOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=pagp_SeniorUnsecuredRevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pagp_GOZoneTermLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=pagp_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pagp_GOZoneTermLoanSeries2009Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pagp_GOZoneTermLoanSeries2010Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt - Commercial Paper and Credit Facilities (Details)	1 Months Ended
Debt - Commercial Paper and Credit Facilities (Details)	Aug. 31, 2021 USD ($) extension	Dec. 31, 2021 USD ($)	Jul. 31, 2021 USD ($)	Aug. 31, 2018 USD ($) debtInstrument
PAA commercial paper notes
Debt Instrument [Line Items]
Maximum aggregate borrowing capacity		$ 2,700,000,000
PAA senior secured hedged inventory facility
Debt Instrument [Line Items]
Maximum aggregate borrowing capacity	$ 1,900,000,000
Committed borrowing capacity	$ 1,350,000,000		$ 1,400,000,000
Number of years by which maturity date of credit facility may be extended	1 year
PAA senior secured hedged inventory facility \| Minimum
Debt Instrument [Line Items]
Credit facility extensions available \| extension	1
PAA senior secured hedged inventory facility \| Letters of credit
Debt Instrument [Line Items]
Committed borrowing capacity	$ 400,000,000
PAA senior unsecured revolving credit facility
Debt Instrument [Line Items]
Maximum aggregate borrowing capacity	2,100,000,000
Committed borrowing capacity	$ 1,350,000,000		$ 1,600,000,000
Number of years by which maturity date of credit facility may be extended	1 year
PAA senior unsecured revolving credit facility \| Minimum
Debt Instrument [Line Items]
Credit facility extensions available \| extension	1
PAA senior unsecured revolving credit facility \| Letters of credit
Debt Instrument [Line Items]
Committed borrowing capacity	$ 400,000,000
GO Zone Term Loans \| Term loan
Debt Instrument [Line Items]
Number of debt instruments \| debtInstrument				2
GO Zone Term Loan Series 2009 \| Term loan
Debt Instrument [Line Items]
Debt instrument face value				$ 100,000,000
GO Zone Term Loan Series 2010 \| Term loan
Debt Instrument [Line Items]
Debt instrument face value				$ 100,000,000