RECEIVABLES, NET AND CONTRACT ASSETS - Financial Assets (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contracts-in-transit	$ 188,200,000	$ 143,800,000
Vehicle receivables	90,900,000	75,600,000
Total contracts-in-transit and vehicle receivables	279,000,000.0	219,400,000
Less: allowance for doubtful accounts	600,000	500,000
Total contracts-in-transit and vehicle receivables, net	278,500,000	218,900,000
Accounts and notes receivable
Accounts and notes receivables	204,700,000	182,200,000
Less: allowance for doubtful accounts	5,500,000	4,300,000
Total accounts and notes receivables, net	199,200,000	177,900,000
Total contract assets	47,900,000	37,500,000
Allowance for doubtful accounts	0	0
Manufacturer receivables
Accounts and notes receivable
Accounts and notes receivables	94,600,000	76,900,000
Parts and service receivables
Accounts and notes receivable
Accounts and notes receivables	68,000,000.0	58,600,000
F&I receivables
Accounts and notes receivable
Accounts and notes receivables	30,000,000.0	29,800,000
Other
Accounts and notes receivable
Accounts and notes receivables	$ 12,100,000	$ 17,000,000.0