Financing Receivables by Aging Category (Detail) - Financial Services - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	$ 14,517.7	$ 13,787.6
Current and up to 30 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	14,463.2	13,741.6
31 - 60 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	18.2	17.8
Greater than 60 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	36.3	28.2
Dealer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	5,117.9	4,644.0
Dealer | Wholesale
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	3,251.9	2,772.1
Dealer | Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	1,866.0	1,871.9
Dealer | Current and up to 30 days past due | Wholesale
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	3,251.8	2,772.1
Dealer | Current and up to 30 days past due | Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	1,866.0	1,871.9
Dealer | 31 - 60 days past due | Wholesale
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	0.1
Customer Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	9,399.8	9,143.6
Customer Retail | Fleet
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	8,148.6	7,808.8
Customer Retail | Owner/Operator
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	1,251.2	1,334.8
Customer Retail | Current and up to 30 days past due | Fleet
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	8,100.2	7,768.5
Customer Retail | Current and up to 30 days past due | Owner/Operator
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	1,245.2	1,329.1
Customer Retail | 31 - 60 days past due | Fleet
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	14.8	14.7
Customer Retail | 31 - 60 days past due | Owner/Operator
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	3.3	3.1
Customer Retail | Greater than 60 days past due | Fleet
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	33.6	25.6
Customer Retail | Greater than 60 days past due | Owner/Operator
Financing Receivable, Recorded Investment, Past Due [Line Items]
Finance Receivable	$ 2.7	$ 2.6