Interim Financial Statements - Business Overview (Details)	6 Months Ended
Jun. 30, 2026 dealership franchise state location
Penske Truck Leasing Co L P \| Penske Corporation
Interim Financial Statements [Line Items]
Penske transportation solutions, ownership percentage	41.10%
Penske Truck Leasing Co L P \| Mitsui and Co
Interim Financial Statements [Line Items]
Penske transportation solutions, ownership percentage	30.00%
Retail automotive dealership
Interim Financial Statements [Line Items]
Total number of owned and operated franchises	362
Retail automotive dealership \| Outside the U.S.
Interim Financial Statements [Line Items]
Number of owned and operated franchises outside US	216
Retail automotive dealership \| United States, United Kingdom, And Australia
Interim Financial Statements [Line Items]
Number of stand-alone used vehicle dealerships operated in United States and United Kingdom \| dealership	13
Retail automotive dealership \| U.S.
Interim Financial Statements [Line Items]
Number of owned and operated franchises in US	146
Number of retail locations operated \| dealership	6
Number of automotive franchises acquired	2
Number of retail automotive franchises sold	4
Retail automotive dealership \| U.K.
Interim Financial Statements [Line Items]
Number of retail locations operated \| dealership	6
Number of retail automotive franchises opened	1
Number of retail automotive franchises closed	3
Number of used vehicle dealerships sold \| dealership	2
Retail automotive dealership \| AUSTRALIA
Interim Financial Statements [Line Items]
Total number of owned and operated franchises \| dealership	3
Number of retail locations operated \| dealership	1
Retail automotive dealership \| GERMANY
Interim Financial Statements [Line Items]
Number of retail automotive franchises opened	1
Retail commercial truck dealership
Interim Financial Statements [Line Items]
Number of operating locations \| location	45
Retail commercial truck dealership \| U.S. and Ontario, Canada
Interim Financial Statements [Line Items]
Number of states with dealerships \| state	10
Penske Truck Leasing Co L P
Interim Financial Statements [Line Items]
Penske transportation solutions, ownership percentage	28.90%

Interim Financial Statements [Line Items]

No definition available.

Name:	pag_InterimFinancialStatementsLineItems
Namespace Prefix:	pag_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Automotive Franchises Acquired

+ References

No definition available.

+ Details

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

- Definition

Represents the number of operating franchises.

+ References

No definition available.

+ Details

Name:	pag_NumberOfOperatingFranchises
Namespace Prefix:	pag_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Total number of owned and operated franchises.

+ References

No definition available.

+ Details

Name:	pag_NumberOfOwnedAndOperatedFranchises
Namespace Prefix:	pag_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of owned and operated franchises in domestic country.

+ References

No definition available.

+ Details

Name:	pag_NumberOfOwnedAndOperatedFranchisesInDomesticCountry
Namespace Prefix:	pag_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of owned and operated franchises in foreign countries.

+ References

No definition available.

+ Details

Name:	pag_NumberOfOwnedAndOperatedFranchisesInForeignCountries
Namespace Prefix:	pag_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number Of Retail Automotive Franchises Closed

+ References

No definition available.

+ Details

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

- Definition

Number Of Retail Automotive Franchises Opened

+ References

No definition available.

+ Details

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

- Definition

Number Of Retail Automotive Franchises Sold

+ References

No definition available.

+ Details

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

- Definition

Number Of States With Locations

+ References

No definition available.

+ Details

Name:	pag_NumberOfStatesWithLocations
Namespace Prefix:	pag_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of used vehicle dealerships operated.

+ References

No definition available.

+ Details

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

- Definition

Number Of Used Vehicle Dealerships Sold

+ References

No definition available.

+ Details

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

- Definition

The number of used vehicle dealerships operated in the United States, United Kingdom, and Australia

+ References

No definition available.

+ Details

Name:	pag_TheNumberOfUsedVehicleDealershipsOperatedInTheUnitedStatesUnitedKingdomAndAustralia
Namespace Prefix:	pag_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage investment held by members or limited partners of limited liability company (LLC) or limited partnership (LP).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482987/272-10-50-3

+ Details

Name:	us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPMembersOrLimitedPartnersOwnershipInterest
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_OwnershipAxis=pag_PenskeTruckLeasingCoLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=pag_PenskeCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=pag_MitsuiAndCoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=pag_RetailAutomotiveDealershipSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=pag_OutsideUSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=pag_UnitedStatesUnitedKingdomAndAustraliaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=country_GB
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=country_AU
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=country_DE
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=pag_RetailCommercialTruckDealershipSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=pag_UnitedStatesAndOntarioCanadaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=pag_PenskeTruckLeasingCoLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: