Represents the amount the reporting entity is obliged to pay to co-obligor.

No definition available.

Name:	pag_AnnualFeeForActingAsCoObligor
Namespace Prefix:	pag_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the maximum liability of the reporting entity for required principal payments on the note by third party.

+ References

No definition available.

+ Details

Name:	pag_MaximumLiabilityForRequiredPrincipalRepaymentOnNotes
Namespace Prefix:	pag_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The percentage of expenses relating to the debt obligation due to the co-obligor as a result of the change in ownership and subsequent relief of debt obligation.

+ References

No definition available.

+ Details

Name:	pag_PercentageOfExpensesRelatingToDebtObligationDueToCoObligorAsResultOfChangeInOwnershipAndSubsequentReliefOfDebtObligation
Namespace Prefix:	pag_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage which the reporting entity has agreed to indemnify a third party for payments the third party is required to pay as co-obligor of debt.

+ References

No definition available.

+ Details

Name:	pag_PercentageOfInterestAgreedToIndemnifyToMakeAnyPaymentsOfPrincipalOrInterest
Namespace Prefix:	pag_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The percentage of interest and principal due to the co-obligor as a result of the change in ownership and subsequent relief of debt obligation.

+ References

No definition available.

+ Details

Name:	pag_PercentageOfInterestAndPrincipalDueToCoObligorAsResultOfChangeInOwnershipAndSubsequentReliefOfDebtObligation
Namespace Prefix:	pag_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of ownership interest purchased in the stock transaction.

+ References

No definition available.

+ Details

Name:	pag_PurchaseOfStockPercentageOfOwnership
Namespace Prefix:	pag_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Surety bonds posted.

+ References

No definition available.

+ Details

Name:	pag_SuretyBondsPosted
Namespace Prefix:	pag_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The number of units or percentage investment held by one or more members or limited partners of the LLC or LP.

+ References

Reference 1: 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_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPMembersOrLimitedPartnersOwnershipInterest
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

Name:	us-gaap_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=pag_HoldingsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pag_SeniorUnsecuredNotesDue2019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=pag_PenskeTruckLeasingCoLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_GuaranteeOfIndebtednessOfOthersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commitments and Contingent Liabilities - Other (Details) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended
	Jul. 26, 2016	Mar. 31, 2015	Dec. 31, 2016
Commitments and Contingent Liabilities
Letters of credit outstanding			$ 32,500
Surety bonds posted			11,400
Holdings \| Holdings Bond
Commitments and Contingent Liabilities
Senior unsecured notes issued			$ 700,000
Senior subordinated convertible notes, interest rate (as a percent)			3.80%
Percentage of interest and principal due to the co-obligor as a result of the change in ownership and subsequent relief of debt obligation		50.10%
Percentage of expenses relating to the debt obligation due to the co-obligor as a result of the change in ownership and subsequent relief of debt obligation		100.00%
PTL
Commitments and Contingent Liabilities
Ownership interest in Penske Truck Leasing Co (as a percent)	9.00%		23.40%
GEC \| PTL
Commitments and Contingent Liabilities
Ownership interest in Penske Truck Leasing Co (as a percent)			15.50%
Mitsui and Co
Commitments and Contingent Liabilities
Purchase of ownership interest		20.00%
Mitsui and Co \| PTL
Commitments and Contingent Liabilities
Ownership interest in Penske Truck Leasing Co (as a percent)			20.00%
Penske Corporation \| PTL
Commitments and Contingent Liabilities
Ownership interest in Penske Truck Leasing Co (as a percent)			41.10%
Guarantee of Indebtedness of Others \| GEC
Commitments and Contingent Liabilities
Percentage of interest agreed to indemnify if GEC required to make any payments of principal or interest			9.00%
Annual fee pay for acting as co-obligor			$ 950
Value of principal repayment included in maximum amount of Company's potential obligations			$ 63,100