Revenues - Other Disclosures (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Revenues
Total revenues	$ 7,468.5	$ 6,906.9	$ 14,807.5	$ 13,882.3
Commercial vehicle distribution and other
Revenues
Payment period			30 days
Total revenues	143.3	140.9	$ 286.9	294.8
Vehicle Sales | Retail Automotive and Retail Commercial Truck Dealership
Revenues
Payment period			30 days
Service and parts | Retail Automotive and Retail Commercial Truck Dealership
Revenues
Payment period			30 days
Service and parts | Commercial vehicle distribution and other
Revenues
Total revenues	68.0	$ 60.5	$ 129.3	$ 115.6
Finance and insurance, net | Retail Automotive and Retail Commercial Truck Dealership
Revenues
Payment period			30 days
Aggregate reserves relating to chargeback activity	$ 40.8		$ 40.8		$ 38.4