Amortized Cost Basis for Finance Receivables that are on Non-accrual Status (Detail) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Financing Receivable, Recorded Investment, Past Due [Line Items]
Amortized cost basis with a specific reserve	$ 135.9	$ 10.0
Amortized cost basis with no specific reserve	5.8	6.1
Total	141.7	16.1
Customer Retail | Fleet
Financing Receivable, Recorded Investment, Past Due [Line Items]
Amortized cost basis with a specific reserve	132.8	8.2
Amortized cost basis with no specific reserve	4.8	5.3
Total	137.6	13.5
Customer Retail | Owner/Oparator
Financing Receivable, Recorded Investment, Past Due [Line Items]
Amortized cost basis with a specific reserve	3.1	1.8
Amortized cost basis with no specific reserve	1.0	0.8
Total	$ 4.1	$ 2.6