Intangible Assets - Information by Segment (Details) - USD ($)	Sep. 30, 2022	Dec. 31, 2021
Goodwill [Line Items]
Goodwill	$ 2,112,900,000	$ 2,124,100,000
Retail automotive dealership
Goodwill [Line Items]
Goodwill	1,581,200,000
Retail commercial truck dealership
Goodwill [Line Items]
Goodwill	461,100,000
Other
Goodwill [Line Items]
Goodwill	70,600,000
Non-Automotive Investments
Goodwill [Line Items]
Goodwill	$ 0