Segment Information - Total Assets, Equity Method Investments, and Capital Expenditures by Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information
Capital expenditures	$ 70.8	$ 99.2	$ 147.4	$ 201.7
Retail Automotive
Segment Reporting Information
Capital expenditures	51.6	90.9	109.5	174.9
Retail Commercial Truck
Segment Reporting Information
Capital expenditures	17.5	6.5	35.3	22.6
Other
Segment Reporting Information
Capital expenditures	1.7	1.8	2.6	4.2
Non-Automotive Investments
Segment Reporting Information
Capital expenditures	$ 0.0	$ 0.0	$ 0.0	$ 0.0