Amortized Cost Basis of Finance Receivables Modified by Portfolio Class (Detail) - Customer Retail - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Financing Receivable Modifications [Line Items]
Amortized cost basis of finance receivables	$ 7.8	$ 0.6	$ 106.8	$ 7.2
Financing receivable modifications percentage	0.20%	0.10%	1.00%	0.10%
Fleet
Financing Receivable Modifications [Line Items]
Amortized cost basis of finance receivables	$ 7.8	$ 0.6	$ 106.4	$ 7.2
Owner/Operator
Financing Receivable Modifications [Line Items]
Amortized cost basis of finance receivables			$ 0.4