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

Represents the maximum aggregate offering price for which an entity may issue and sell common units through a specific equity distribution agreement.

+ References

No definition available.

+ Details

Name:	pagp_MaximumAggregateCommonStockOfferPrice
Namespace Prefix:	pagp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	pagp_PartnersCapitalAndDistributionLineItems
Namespace Prefix:	pagp_
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

+ 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

Amount of increase in noncontrolling interest from subsidiary issuance of equity interests to noncontrolling interest holders.

+ References

No definition available.

+ Details

Name:	us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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

+ References

+ Details

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

- Definition

Total units issued during the year due to the sale of units. All partners include 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 1

-Subparagraph (SX 210.3-04)

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

Reference 3: 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

+ Details

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

- Definition

The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

+ References

No definition available.

+ Details

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

- Definition

Amount of cash inflow (outflow) from long-term debt wholly or partially secured by collateral. Excludes tax exempt secured debt.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

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

Partners' Capital and Distributions (Details 3) (USD $) In Millions, except Per Share data, unless otherwise specified	9 Months Ended		1 Months Ended		9 Months Ended		9 Months Ended		0 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2013 AAP term loan	Sep. 30, 2014 PAA	Sep. 30, 2014 PAA PAA Continuous Offering Program	Aug. 31, 2014 PAA August 2014 Equity Distribution Agreement	Sep. 30, 2014 SLC Pipeline LLC	Sep. 30, 2014 AAP	Aug. 14, 2014 Second Quarter Distribution PAA	Sep. 30, 2014 Second Quarter Distribution PAA	Aug. 14, 2014 Second Quarter Distribution AAP	Sep. 30, 2014 Second Quarter Distribution AAP	May 15, 2014 First Quarter Distribution PAA	Sep. 30, 2014 First Quarter Distribution PAA	May 15, 2014 First Quarter Distribution AAP	Sep. 30, 2014 First Quarter Distribution AAP	Feb. 14, 2014 Fourth quarter distribution PAA	Sep. 30, 2014 Fourth quarter distribution PAA	Feb. 14, 2014 Fourth quarter distribution AAP	Sep. 30, 2014 Fourth quarter distribution AAP	Nov. 14, 2014 Third quarter distribution PAA Subsequent Event	Sep. 30, 2014 Third quarter distribution PAA Subsequent Event	Nov. 14, 2014 Third quarter distribution AAP Subsequent Event	Sep. 30, 2014 Third quarter distribution AAP Subsequent Event
Partners Capital and Distribution
Units Issued (in units)					11.8
Proceeds from Sale	$ 655	$ 431			$ 655
Maximum aggregate offer price of common stock						900
Noncontrolling interests, ownership percentage of noncontrolling owners				98.00%			25.00%	78.00%
Date Declared										Jul. 08, 2014				Apr. 07, 2014				Jan. 09, 2014				Oct. 08, 2014
Distribution Date										Aug. 14, 2014		Aug. 14, 2014		May 15, 2014		May 15, 2014		Feb. 14, 2014		Feb. 14, 2014		Nov. 14, 2014		Nov. 14, 2014
Unitholders of record, date																						Oct. 31, 2014		Oct. 31, 2014
Distributions received by AAP from PAA											122				115				107				129
Cash Reserves											(3)				(4)				(3)				(4)
Distributions paid to limited partners									238		119		229		111		221		104		245		125
Distributions to AAP - Incentive									117				110				102				124
Distributions to AAP - 2%									5				5				5				5
Total distributions paid during the period	1,024	1,188							360				344				328				374
Distribution per limited partner unit (in dollars per unit)									$ 0.6450				$ 0.6300				$ 0.6150				$ 0.6600
Distributions to noncontrolling interests							2				94				88				87				99
Distributions to PAGP											25				23				17				26
Increase in term loan		300	300
Net proceeds			$ 299