Represents the percentage of additional investment ownership interest acquired during the period.

No definition available.

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Namespace Prefix:	pag_
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- Definition

The percentage of investment ownership.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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Period Type:	instant

- Definition

Represents the ownership interest acquired by the entity during the period.

+ References

No definition available.

+ Details

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

- Definition

Represents the minimum number of vehicle brands offered.

+ References

No definition available.

+ Details

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Namespace Prefix:	pag_
Data Type:	xbrli:integerItemType
Balance Type:	na
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- Definition

Represents the minimum number of dealership locations wherein the vehicles were distributed and sold.

+ References

No definition available.

+ Details

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

- Definition

Represents the minimum number of vehicles retailed and wholesaled.

+ References

No definition available.

+ Details

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

- Definition

Represents the number of dealerships operated.

+ References

No definition available.

+ Details

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

- Definition

Number of franchises acquired.

+ References

No definition available.

+ Details

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

- Definition

Represents the number of franchises disposed of by the entity during the period.

+ References

No definition available.

+ Details

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

- Definition

Represents the number of full service retail locations acquired.

+ References

No definition available.

+ Details

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

- Definition

Represents the number of full service retail locations operated by the equity method investee.

+ References

No definition available.

+ Details

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

- 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:	duration

- Definition

Total number of owned and operated franchises.

+ References

No definition available.

+ Details

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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

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

- Definition

Represents the number of retail commercial vehicle dealerships owned by the reporting entity.

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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Name:	us-gaap_SalesRevenueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of units or percentage investment held in the subsidiary by the limited liability company or limited partnership.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 320
-Section S99
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611443-123010

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Data Type:	num:percentItemType
Balance Type:	na
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Name:	pag_TypeOfDealershipAxis=pag_MINIDealershipMember
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Name:	us-gaap_BusinessAcquisitionAxis=pag_HarperTruckCentresMember
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Name:	dei_LegalEntityAxis=us-gaap_PartnershipInterestMember
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Name:	us-gaap_FranchisorDisclosureAxis=pag_RetailAutomotiveDealershipMember
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Name:	dei_EntityByLocationAxis=pag_UnitedKingdomMember
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Interim Financial Statements - Business Overview (Details) $ in Millions	1 Months Ended		3 Months Ended		12 Months Ended
	Apr. 30, 2016 item	Feb. 28, 2015 item	Mar. 31, 2016 USD ($) item	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	Jan. 31, 2016	Oct. 31, 2014
Interim Financial Statements
Total revenues \| $			$ 4,824.6	$ 4,482.9
German Automotive Dealership Group
Interim Financial Statements
Additional ownership interest acquired (as a percent)			8.00%
Ownership interest (as a percent)			68.00%
Nicole Group \| BMW Dealership
Interim Financial Statements
Number of dealerships operated			4
Nicole Group \| MINI Dealership
Interim Financial Statements
Number of dealerships operated			3
Harper Truck Centres
Interim Financial Statements
Number of dealerships operated	5
Penske Truck Leasing Co., L.P.
Interim Financial Statements
Limited partnership interest (as a percent)			9.00%	9.00%
Retail Automotive Dealership
Interim Financial Statements
Total number of owned and operated franchises			349
Number of owned and operated franchises in US			179
Number of owned and operated franchises outside US			170
Minimum number of vehicles retailed and wholesaled			134,000
Minimum number of vehicle brands offered			40
Number of franchises disposed			7
Retail Automotive Dealership \| Nicole Group
Interim Financial Statements
Ownership percentage of Equity Method Investment						49.00%
Retail Automotive Dealership \| UK
Interim Financial Statements
Number of acquired franchises			1
Retail Commercial Truck Dealership
Interim Financial Statements
Number of operating locations			14
Number of full service retail locations operated			10
Number of full service retail locations acquired		2
Retail Commercial Truck Dealership \| PTG
Interim Financial Statements
Ownership interest (as a percent)			96.00%
Ownership acquired (as a percentage)					5.00%
Ownership percentage of Equity Method Investment							32.00%
Commercial Vehicle Distribution
Interim Financial Statements
Minimum number of dealership locations			70
Number of commercial vehicle dealerships			3
Automotive dealership revenues \| Geographic \| U.S. and Puerto Rico
Interim Financial Statements
Automotive dealership revenue (as a percent)			57.00%
Automotive dealership revenues \| Geographic \| Outside the U.S.
Interim Financial Statements
Automotive dealership revenue (as a percent)			43.00%
Automotive dealership revenues \| Premium brands
Interim Financial Statements
Automotive dealership revenue (as a percent)			72.00%
Retail Automotive Dealership
Interim Financial Statements
Total revenues \| $			$ 4,512.9	$ 4,186.8	$ 17,900.0
Retail Commercial Truck Dealership
Interim Financial Statements
Total revenues \| $			206.7	192.7
Commercial Vehicle Distribution and Other
Interim Financial Statements
Total revenues \| $			$ 105.0	$ 103.4