Long-Term Debt - U.K. Credit Agreement (Details) £ in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2025 USD ($)	Sep. 30, 2025 GBP (£)	Dec. 31, 2024 USD ($)
Debt Instrument [Line Items]
Outstanding debt \| $	$ 1,571.0		$ 1,852.0
U.K. credit agreement — revolving credit line
Debt Instrument [Line Items]
Maximum credit available		£ 200.0
Additional facility capacity under accordion feature		100.0
Outstanding debt	$ 40.3	£ 30.0	$ 171.4
U.K. credit agreement — revolving credit line \| Minimum
Debt Instrument [Line Items]
Line of credit basis spread on variable rate, increase (decrease) (as a percent)	1.10%
U.K. credit agreement — revolving credit line \| Maximum
Debt Instrument [Line Items]
Line of credit basis spread on variable rate, increase (decrease) (as a percent)	2.10%

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.

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+ Details

- Definition

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

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+ Details

PENSKE AUTOMOTIVE GROUP, INC. 10-Q