Intangible Assets - Narrative (Details) - USD ($)	Mar. 31, 2025	Dec. 31, 2024
Goodwill [Line Items]
Goodwill	$ 2,383,300,000	$ 2,371,300,000
Retail automotive dealership
Goodwill [Line Items]
Goodwill	1,815,200,000
Retail commercial truck dealership
Goodwill [Line Items]
Goodwill	497,500,000
Other
Goodwill [Line Items]
Goodwill	70,600,000
Non-Automotive Investments
Goodwill [Line Items]
Goodwill	$ 0