Amortized Cost Basis of Finance Receivables that are on Non-accrual Status (Detail) - Financial Services - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Recorded Investment, Past Due [Line Items]
Amortized cost basis of finance receivables that are on non-accrual status	$ 78.8	$ 87.9
Dealer | Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Amortized cost basis of finance receivables that are on non-accrual status	1.1	1.2
Customer Retail | Fleet
Financing Receivable, Recorded Investment, Past Due [Line Items]
Amortized cost basis of finance receivables that are on non-accrual status	70.4	78.6
Customer Retail | Owner/Operator
Financing Receivable, Recorded Investment, Past Due [Line Items]
Amortized cost basis of finance receivables that are on non-accrual status	$ 7.3	$ 8.1