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

No definition available.

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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
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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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- Definition

Represents the minimum number of vehicles retailed and wholesaled.

+ References

No definition available.

+ Details

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- Definition

Number of franchises acquired.

+ References

No definition available.

+ Details

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- Definition

Number of brands represented by franchises awarded to the reporting entity.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
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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
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- Definition

Represents the number of operating franchises.

+ References

No definition available.

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Data Type:	xbrli:integerItemType
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- Definition

Total number of owned and operated franchises.

+ References

No definition available.

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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.

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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.

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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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- Definition

Represents the number of 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 smart 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
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- References

No definition available.

+ Details

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

This element represents the aggregate cost of investments accounted for under the equity method of accounting.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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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.

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-Publisher FASB
-Name Accounting Standards Codification
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Data Type:	num:percentItemType
Balance Type:	na
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- 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.

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Interim Financial Statements - Business Overview (Details) $ in Millions				1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017 item	Jul. 27, 2016 USD ($)	Jul. 26, 2016	Dec. 31, 2016 item	Apr. 30, 2016 item	Jun. 30, 2017 USD ($) item	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) item	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Interim Financial Statements
Total revenues \| $						$ 5,383.4	$ 5,254.1	$ 10,464.5	$ 10,078.7
PTL
Interim Financial Statements
Ownership acquired (as a percent)		14.40%
Ownership interest in Penske Truck Leasing Co (as a percent)	23.40%		9.00%
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	354					354		354
Number of owned and operated franchises in US	162					162		162
Number of owned and operated franchises outside US	192					192		192
Minimum number of vehicles retailed and wholesaled								315,200
Minimum number of vehicle brands offered								40
Number of acquired franchises								6
Number of franchises awarded to the reporting entity								2
Number of franchises disposed								9
Number of smart franchises disposed								5
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
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								10
New Jersey \| Retail Automotive Dealership
Interim Financial Statements
Number of acquired franchises								2
Arizona \| 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)								58.00%
Automotive dealership revenues \| Geographic \| Outside the U.S.
Interim Financial Statements
Automotive dealership revenue (as a percent)								42.00%
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 \| $						$ 5,040.7	4,836.8	$ 9,797.1	9,349.7	$ 18,700.0
Retail Commercial Truck Dealership
Interim Financial Statements
Total revenues \| $						228.5	309.5	440.2	516.2
Commercial Vehicle Distribution and Other
Interim Financial Statements
Total revenues \| $						$ 114.2	$ 107.8	$ 227.2	$ 212.8