Revenues - Retail Commercial Truck Dealership (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenues
Total revenues	$ 7,468.5	$ 6,906.9	$ 14,807.5	$ 13,882.3
Retail commercial truck dealership
Revenues
Total revenues	919.2	768.7	1,814.8	1,561.0
New truck | Retail commercial truck dealership
Revenues
Total revenues	616.4	447.3	1,216.6	919.0
Used truck | Retail commercial truck dealership
Revenues
Total revenues	52.4	78.7	101.9	179.0
Finance and insurance, net | Retail commercial truck dealership
Revenues
Total revenues	5.0	4.5	10.0	10.9
Service and parts | Retail commercial truck dealership
Revenues
Total revenues	232.1	219.6	460.1	416.6
Other | Retail commercial truck dealership
Revenues
Total revenues	$ 13.3	$ 18.6	$ 26.2	$ 35.5