Name:	pagp_EquityBasedCompensationFairValueFutureAmortizationAbstract
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The amount of amortization expense expected to be recognized during the fifth twelve-month period following the balance sheet date for the amortization of the unrecognized expense based on fair value of outstanding awards related to equity compensation plans.

No definition available.

Name:	pagp_EquityBasedCompensationFairValueFutureAmortizationExpenseYearFive
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The amount of amortization expense expected to be recognized during the fourth twelve-month period following the balance sheet date for the amortization of the unrecognized expense based on fair value of outstanding awards related to equity compensation plans.

No definition available.

Name:	pagp_EquityBasedCompensationFairValueFutureAmortizationExpenseYearFour
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The amount of amortization expense expected to be recognized during the twelve-month period following the balance sheet date for the amortization of the unrecognized expense based on fair value of outstanding awards related to equity compensation plans.

No definition available.

Name:	pagp_EquityBasedCompensationFairValueFutureAmortizationExpenseYearOne
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The amount of amortization expense expected to be recognized during the third twelve-month period following the balance sheet date for the amortization of the unrecognized expense based on fair value of outstanding awards related to equity compensation plans.

No definition available.

Name:	pagp_EquityBasedCompensationFairValueFutureAmortizationExpenseYearThree
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The amount of amortization expense expected to be recognized during the second twelve-month period following the balance sheet date for the amortization of the unrecognized expense based on fair value of outstanding awards related to equity compensation plans.

No definition available.

Name:	pagp_EquityBasedCompensationFairValueFutureAmortizationExpenseYearTwo
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Other Consolidated Equity Compensation Information [Abstract]

No definition available.

Name:	pagp_OtherConsolidatedEquityCompensationInformationAbstract
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Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Vested In Period, Total Settlement Fair Value

No definition available.

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Share Based Compensation Arrangement By Share Based Payment Award, Vested In Period, Cash Settled

No definition available.

Name:	pagp_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestedInPeriodCashSettled
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Data Type:	xbrli:monetaryItemType
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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Name:	us-gaap_AllocatedShareBasedCompensationExpense
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Unrecognized cost of unvested share-based compensation awards.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901