Intangible Assets - Changes in Goodwill by Reportable Segment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Goodwill
Beginning balance	$ 2,124,100,000	$ 1,928,400,000
Additions	93,800,000	209,600,000
Disposals	(1,900,000)	(600,000)
Foreign currency translation	(61,300,000)	(13,300,000)
Ending balance	2,154,700,000	2,124,100,000
Retail automotive dealership
Goodwill
Beginning balance	1,622,200,000	1,534,800,000
Additions	49,900,000	96,800,000
Disposals	(1,900,000)	(600,000)
Foreign currency translation	(52,600,000)	(8,800,000)
Ending balance	1,617,600,000	1,622,200,000
Retail commercial truck dealership
Goodwill
Beginning balance	422,300,000	309,400,000
Additions	43,900,000	112,800,000
Disposals	0	0
Foreign currency translation	(3,900,000)	100,000
Ending balance	462,300,000	422,300,000
Other
Goodwill
Beginning balance	79,600,000	84,200,000
Additions	0	0
Disposals	0	0
Foreign currency translation	(4,800,000)	(4,600,000)
Ending balance	74,800,000	$ 79,600,000
Non-Automotive Investments
Goodwill
Ending balance	$ 0