Intangible Assets - Narrative (Details) - USD ($)	Jun. 30, 2025	Dec. 31, 2024
Goodwill [Line Items]
Goodwill	$ 2,431,900,000	$ 2,371,300,000
Retail automotive dealership
Goodwill [Line Items]
Goodwill	1,855,500,000
Retail commercial truck dealership
Goodwill [Line Items]
Goodwill	502,200,000
Other
Goodwill [Line Items]
Goodwill	74,200,000
Non-Automotive Investments
Goodwill [Line Items]
Goodwill	$ 0