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

No definition available.

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Balance Type:	na
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- Definition

Represents the minimum number of vehicle brands offered.

+ References

No definition available.

+ Details

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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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Data Type:	xbrli:integerItemType
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- Definition

Represents the minimum number of vehicles retailed and wholesaled.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
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- Definition

Number of franchises acquired.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
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- Definition

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

+ References

No definition available.

+ Details

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- Definition

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

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
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- Definition

Represents the number of open points granted.

+ 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 number of operating franchises.

+ References

No definition available.

+ Details

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

Total number of owned and operated franchises.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
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- Definition

Number of owned and operated franchises in domestic country.

+ References

No definition available.

+ Details

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

Represents the number of retail locations acquired.

+ References

No definition available.

+ Details

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Namespace Prefix:	pag_
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- References

No definition available.

+ Details

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- 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
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+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the aggregate cost of investments 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 210
-SubTopic 10
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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
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-Section S99
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Interim Financial Statements - Business Overview (Details) $ in Millions			1 Months Ended		3 Months Ended		12 Months Ended
	Jul. 27, 2016 USD ($)	Jul. 26, 2016	Dec. 31, 2016 item	Apr. 30, 2016 item	Mar. 31, 2017 USD ($) item	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Interim Financial Statements
Total revenues \| $					$ 5,081.1	$ 4,824.6
PTL
Interim Financial Statements
Ownership acquired (as a percent)	14.40%
Ownership interest in Penske Truck Leasing Co (as a percent)		9.00%			23.40%
Cost of acquisition \| $	$ 498.5
CarSense
Interim Financial Statements
Number of retail locations acquired					5
CarShop
Interim Financial Statements
Number of retail locations acquired					5
Retail Automotive Dealership
Interim Financial Statements
Total number of owned and operated franchises					357
Number of owned and operated franchises in US					165
Number of owned and operated franchises outside US					192
Minimum number of vehicles retailed and wholesaled					154,000
Minimum number of vehicle brands offered					40
Number of acquired franchises					4
Number of open points granted					2
Number of franchises disposed					4
Retail Automotive Dealership \| CarSense
Interim Financial Statements
Number of retail locations acquired					5
Retail Automotive Dealership \| CarShop
Interim Financial Statements
Number of retail locations acquired					5
Retail Commercial Truck Dealership \| PTG
Interim Financial Statements
Number of operating locations					20
Number of full service retail locations operated					14
Number of retail locations acquired			2	4
Commercial Vehicle Distribution
Interim Financial Statements
Minimum number of dealership locations					70
Number of retail dealerships owned by the reporting entity					8
New Jersey \| Retail Automotive Dealership
Interim Financial Statements
Number of acquired franchises					2
Germany \| Retail Automotive Dealership
Interim Financial Statements
Number of acquired franchises					2
Automotive dealership revenues \| Geographic \| U.S. and Puerto Rico
Interim Financial Statements
Automotive dealership revenue (as a percent)					56.00%
Automotive dealership revenues \| Geographic \| Outside the U.S.
Interim Financial Statements
Automotive dealership revenue (as a percent)					44.00%
Automotive dealership revenues \| Premium brands
Interim Financial Statements
Automotive dealership revenue (as a percent)					70.00%
Penske Corporation \| PTL
Interim Financial Statements
Ownership interest in Penske Truck Leasing Co (as a percent)					41.10%
Mitsui and Co \| PTL
Interim Financial Statements
Ownership interest in Penske Truck Leasing Co (as a percent)					20.00%
GEC \| PTL
Interim Financial Statements
Ownership interest in Penske Truck Leasing Co (as a percent)					15.50%
Retail Automotive Dealership
Interim Financial Statements
Total revenues \| $					$ 4,756.4	4,512.9	$ 18,700.0
Retail Commercial Truck Dealership
Interim Financial Statements
Total revenues \| $					211.7	206.7
Commercial Vehicle Distribution and Other
Interim Financial Statements
Total revenues \| $					$ 113.0	$ 105.0