v3.26.1
Summary of Amortized Cost Basis of Financing Receivables by Aging Category (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due $ 10,934.3 $ 11,058.1
Current and up to 30 days past due    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 10,808.4 10,892.0
31 - 60 days past due    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 32.5 80.1
Greater than 60 days past due    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 93.4 86.0
Dealer    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 4,435.3 4,648.4
Dealer | Wholesale    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 2,308.0 2,440.8
Dealer | Wholesale | Current and up to 30 days past due    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 2,308.0 2,440.8
Dealer | Retail    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 2,127.3 2,207.6
Dealer | Retail | Current and up to 30 days past due    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 2,127.3 2,207.6
Customer Retail    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 6,499.0 6,409.7
Customer Retail | Fleet    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 5,880.6 5,808.3
Customer Retail | Fleet | Current and up to 30 days past due    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 5,761.5 5,657.6
Customer Retail | Fleet | 31 - 60 days past due    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 28.8 71.0
Customer Retail | Fleet | Greater than 60 days past due    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 90.3 79.7
Customer Retail | Owner/Operator    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 618.4 601.4
Customer Retail | Owner/Operator | Current and up to 30 days past due    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 611.6 586.0
Customer Retail | Owner/Operator | 31 - 60 days past due    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due 3.7 9.1
Customer Retail | Owner/Operator | Greater than 60 days past due    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables, past due $ 3.1 $ 6.3