Distributions received from a consolidated subsidiary, which are eliminated in consolidation.

No definition available.

Name:	pagp_DistributionsReceivedFromConsolidatedSubsidiary
Namespace Prefix:	pagp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The percentage of the distribution that the general partner is entitled to based on its ownership.

+ References

No definition available.

+ Details

Name:	pagp_GeneralPartnerDistributionPercentage
Namespace Prefix:	pagp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	pagp_PartnersCapitalAndDistributionLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Reduction in cash available for distribution for reserves established by the general partner of the entity for future requirements.

+ References

No definition available.

+ Details

Name:	pagp_ReductionInCashAvailableForDistribution
Namespace Prefix:	pagp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents disclosure of the aggregate cash dividends paid to the entity by consolidated subsidiaries.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 235

-Section S99

-Paragraph 2

-Subparagraph (SX 210.9-06)

-URI http://asc.fasb.org/extlink&oid=6882215&loc=d3e537971-122884

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 06

-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph b

-Article 12

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 3

-Subparagraph (SX 210.12-04.(b))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690

+ Details

Name:	us-gaap_CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Date of record for distribution of cash or unit to limited partner of limited partnership (LP), in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

+ Details

Name:	us-gaap_DistributionMadeToLimitedPartnerDateOfRecord
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Date of declaration for distribution of cash or unit to limited partner of limited partnership (LP), in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_DistributionMadeToLimitedPartnerDeclarationDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Date of distribution for distribution of cash or unit to limited partner of limited partnership (LP), in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_DistributionMadeToLimitedPartnerDistributionDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Cash dividends declared or paid to each outstanding limited partnership unit during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 4

-Section F

+ Details

Name:	us-gaap_DistributionsPerLimitedPartnershipUnitOutstanding
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Distributions from earnings to the general partner of a partnership included in the consolidated financial statements.

+ References

No definition available.

+ Details

Name:	us-gaap_GeneralPartnerDistributions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of incentive obligation paid in cash or stock during the period to a limited liability corporation managing member or limited partnership general partner.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

Name:	us-gaap_IncentiveDistributionDistributionPerYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The total amount of distributions to limited partners.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 5

-Subparagraph (SAB TOPIC 4.F)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

+ Details

Name:	us-gaap_LimitedPartnersCapitalAccountDistributionAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Decrease in noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders.

+ References

+ Details

Name:	us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

Name:	us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Total distributions to each class of partners (i.e., general, limited and preferred partners).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Period Type:

Partners' Capital and Distributions (Detail 3) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Feb. 13, 2015	May 15, 2015
Partners Capital and Distribution
Total distributions paid during the period	$ 388	$ 326
PAA
Partners Capital and Distribution
Noncontrolling interests in subsidiaries (as a percent)	98.00%
Percentage of distribution amount to the general partner before incentive distributions	2.00%
PAA \| Fourth quarter 2014 distribution
Partners Capital and Distribution
Declaration date of quarterly distribution	Jan. 08, 2015
Distribution Date	Feb. 13, 2015
Distributions paid to limited partners			254
Distributions to AAP - 2%			5
Distributions to AAP - Incentive			131
Total distributions paid during the period			390
Distribution per limited partner unit			$ 0.6750
PAA \| Subsequent Event \| First quarter 2015 distribution
Partners Capital and Distribution
Declaration date of quarterly distribution	Apr. 07, 2015
Distribution Date	May 15, 2015
Unitholders of record, date	May 01, 2015
Distributions paid to limited partners				272
Distributions to AAP - 2%				6
Distributions to AAP - Incentive				142
Total distributions paid during the period				420
Distribution per limited partner unit				$ 0.6850
AAP
Partners Capital and Distribution
Noncontrolling interests in subsidiaries (as a percent)	63.00%
AAP \| Fourth quarter 2014 distribution
Partners Capital and Distribution
Distribution Date	Feb. 13, 2015
Distributions received by AAP from PAA			136
Cash Reserves			(3)
Distributions paid to limited partners			133
Distributions to noncontrolling interests			91
Distributions to PAGP			42
AAP \| Subsequent Event \| First quarter 2015 distribution
Partners Capital and Distribution
Distribution Date	May 15, 2015
Unitholders of record, date	May 01, 2015
Distributions received by AAP from PAA				148
Cash Reserves				(3)
Distributions paid to limited partners				145
Distributions to noncontrolling interests				95
Distributions to PAGP				50
SLC Pipeline LLC
Partners Capital and Distribution
Noncontrolling interests in subsidiaries (as a percent)	25.00%
Distributions to noncontrolling interests	$ 1