Auto Loans Receivable - Financing Receivable, Past Due (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Total auto loans receivable	$ 451.2	$ 377.0
Total Past Due
Financing Receivable, Past Due [Line Items]
Total auto loans receivable	29.2	19.7
31-60 Days
Financing Receivable, Past Due [Line Items]
Total auto loans receivable	20.7	13.0
61-90 Days
Financing Receivable, Past Due [Line Items]
Total auto loans receivable	5.4	4.1
Greater than 90 Days
Financing Receivable, Past Due [Line Items]
Total auto loans receivable	3.1	2.6
Current
Financing Receivable, Past Due [Line Items]
Total auto loans receivable	$ 422.0	$ 357.3