Goodwill And Intangible Assets, Net (Narrative) (Details) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2025 USD ($)	Jun. 30, 2025 USD ($) store	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)
Goodwill [Line Items]
Goodwill impairment	$ 0.0		$ 0.0	$ 65.3	$ 0.0
Franchise rights impairment, number of stores | store		9
Franchise rights impairment	$ 0.0		$ 0.0	71.7	0.0
Reporting Unit, Domestic
Goodwill [Line Items]
Goodwill impairment				0.0
Reporting Unit, Import
Goodwill [Line Items]
Goodwill impairment				0.0
Reporting Unit, Premium Luxury
Goodwill [Line Items]
Goodwill impairment				0.0
Reporting Unit, AN Finance
Goodwill [Line Items]
Goodwill impairment				0.0
Reporting Unit, Other
Goodwill [Line Items]
Goodwill impairment				65.3
Fair Value, Nonrecurring [Member]
Goodwill [Line Items]
Goodwill impairment				65.3	0.0
Fair Value, Nonrecurring [Member] | Reporting Unit, Mobile Service
Goodwill [Line Items]
Goodwill impairment		$ 65.3
Fair Value, Nonrecurring [Member] | Franchise Rights
Goodwill [Line Items]
Franchise rights impairment		$ 71.7		$ 71.7	$ 0.0