Revenues - Retail Commercial Truck Dealership (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Revenues
Total revenues	$ 7,604.5	$ 7,447.8
Retail commercial truck dealership
Revenues
Total revenues	823.7	791.8
New truck | Retail commercial truck dealership
Revenues
Total revenues	527.2	494.2
Used truck | Retail commercial truck dealership
Revenues
Total revenues	63.8	62.4
Finance and insurance, net | Retail commercial truck dealership
Revenues
Total revenues	4.5	5.3
Service and parts | Retail commercial truck dealership
Revenues
Total revenues	222.0	223.6
Other | Retail commercial truck dealership
Revenues
Total revenues	$ 6.2	$ 6.3