Floor Plan Notes Payable - Trade and Non-trade (Details)	6 Months Ended
Jun. 30, 2013
Floor Plan Notes Payable - Trade and Non-trade
Maturity period of floor plan arrangements outside the U.S. if not payable on demand	90 days

The maximum period of original maturity for floor plans outside of the United States.

No definition available.

Name:	pag_FloorPlanNotesPayableForeignMaximumDuration
Namespace Prefix:	pag_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration