The period in which the lender has the ability to call the debt.

No definition available.

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

- Definition

Number of facilities.

+ References

No definition available.

+ Details

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

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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

- Definition

Description of reference rate used for variable rate of debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
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+ Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=pag_AustraliaCapitalLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=pag_AustraliaCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=pag_AustralianBBSW30DayBillRateMember
Namespace Prefix:
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Long-Term Debt - Australia Loan Agreements (Details) $ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) facility	Dec. 31, 2022 AUD ($)	Dec. 31, 2021 USD ($)
Debt Instrument
Long-term debt	$ 1,622.1		$ 1,474.0
Australia capital loan agreement
Debt Instrument
Number of facilities \| facility	2
Debt instrument, term	3 years
Line of credit basis spread on variable rate (as a percent)	3.00%
Maximum credit available		$ 35.4
Long-term debt	$ 0.0		26.6
Australia working capital loan agreement
Debt Instrument
Debt instrument, term	1 year
Line of credit basis spread on variable rate (as a percent)	3.00%
Maximum credit available		50.0
Long-term debt	$ 0.0		0.0
Australia credit agreement
Debt Instrument
Line of credit basis spread on variable rate (as a percent)	2.29%
Maximum credit available		75.0
Call period	6 months
Long-term debt	$ 21.6	$ 31.7	$ 0.0
Australia credit agreement \| Australian BBSW 30-Day Bill Rate
Debt Instrument
Base rate of interest on loans	30-day Bill Rate