Name:	pag_BusinessCombinationProFormaInformationPreTaxIncomeOfAcquireeSinceAcquisitionDateActual
Namespace Prefix:	pag_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Number of franchises acquired.

No definition available.

Name:	pag_NumberOfFranchisesAcquired
Namespace Prefix:	pag_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the number of full service retail locations acquired.

No definition available.

Name:	pag_NumberOfFullServiceRetailLocationsAcquired
Namespace Prefix:	pag_
Data Type:	xbrli:integerItemType
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_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)
-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463