Name:	pagp_AnnualizedDistributionProbableOfOccurring
Namespace Prefix:	pagp_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

The number of outstanding distribution equivalent rights that are vested as of the balance sheet date.

No definition available.

Name:	pagp_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsIncludingDistributionEquivalentRightsEarnedNumber
Namespace Prefix:	pagp_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

This element represents the portion of outstanding units, which include distribution equivalent rights that entitles the grantee to a cash payment equal to the cash distribution paid on an outstanding common unit.

No definition available.

Name:	pagp_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsIncludingDistributionEquivalentRightsOutstanding
Namespace Prefix:	pagp_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, outstanding as of the balance sheet date and expected to vest, based on expected achievement of applicable performance conditions.

No definition available.

Name:	pagp_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsTotalExpectedToVest
Namespace Prefix:	pagp_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, outstanding as of the balance sheet date and expected to vest in the fourth fiscal year following the balance sheet date, based on expected achievement of applicable performance conditions.

No definition available.

Name:	pagp_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestingInYearFour
Namespace Prefix:	pagp_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, outstanding as of the balance sheet date and expected to vest in the next fiscal year following the balance sheet date, based on expected achievement of applicable performance conditions.

No definition available.

Name:	pagp_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestingInYearOne
Namespace Prefix:	pagp_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, outstanding as of the balance sheet date and expected to vest in the third fiscal year following the balance sheet date, based on expected achievement of applicable performance conditions.

No definition available.

Name:	pagp_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestingInYearThree
Namespace Prefix:	pagp_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, outstanding as of the balance sheet date and expected to vest in the second fiscal year following the balance sheet date, based on expected achievement of applicable performance conditions.

No definition available.

Name:	pagp_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestingInYearTwo
Namespace Prefix:	pagp_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, outstanding as of the balance sheet date and expected to vest after the fourth fiscal year following the balance sheet date, based on expected achievement of applicable performance conditions.

No definition available.

Name:	pagp_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestingThereafter
Namespace Prefix:	pagp_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The annualized distribution level that must be reached for awards outstanding under the equity compensation plan to vest.

No definition available.

Name:	pagp_ShareBasedCompensationSharesOutstandingUnderEquityCompensationPlansAnnualizedDistributionLevelRequiredForVesting
Namespace Prefix:	pagp_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

Number of units for which the vesting criteria was modified during the period.

No definition available.

Name:	pagp_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsModifiedinPeriod
Namespace Prefix:	pagp_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Represents the number of units that would have vested based on the passage of time but will vest earlier following the modification of vesting criteria.

No definition available.

Name:	pagp_UnitsThatWouldHaveVestedBasedOnPassageOfTimeButWillVestEarlierFollowingModification
Namespace Prefix:	pagp_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

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.

No definition available.

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

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Name:	us-gaap_PlanNameAxis=pagp_PlainsAllAmericanLongTermIncentivePlansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_LegalEntityAxis=pagp_PlainsAllAmericanPipelineLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PlanNameAxis=pagp_PlainsAllAmerican2013LongTermIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PlanNameAxis=pagp_PlainsAllAmericanPNGSuccessorLongTermIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: