CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Statement of Cash Flows [Abstract]
Repayment of sellers' floor plan notes payable dealership acquisitions	$ 16.5	$ 0.0

Repayment of sellers' floor plan notes payable, dealership acquisitions.

No definition available.

Name:	pag_RepaymentOfSellersFloorPlanNotesPayableDealershipAcquisitions
Namespace Prefix:	pag_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration