Revenues - Retail Commercial Truck Dealership (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues
Total revenues	$ 25,554.7	$ 20,443.9	$ 23,179.4
Retail commercial truck dealership
Revenues
Total revenues	2,465.7	2,060.9	2,050.5
New vehicle | Retail commercial truck dealership
Revenues
Total revenues	1,540.1	1,315.9	1,347.2
Used vehicle | Retail commercial truck dealership
Revenues
Total revenues	270.6	194.2	117.0
Finance and insurance, net | Retail commercial truck dealership
Revenues
Total revenues	16.8	14.5	12.4
Service and parts | Retail commercial truck dealership
Revenues
Total revenues	609.0	478.1	503.3
Other | Retail commercial truck dealership
Revenues
Total revenues	$ 29.2	$ 58.2	$ 70.6