Finance and Other Receivables (Detail) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retail loans		$ 5,028.2	$ 4,627.0
Retail financing leases		1,710.4	1,433.5
Dealer wholesale financing		1,953.3	1,093.2
Dealer master notes		509.2	377.0
Operating lease receivables and other		65.3	49.4
Total portfolio		9,266.4	7,580.1
Less allowance for credit losses		(61.0)	(61.7)	$ (65.7)	$ (68.2)
Finance and other receivables, net		9,205.4	7,518.4
Loans and Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for credit losses		(58.6)	(59.7)
Dealer | Wholesale
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for credit losses		(1.0)	(1.0)	(1.0)	(1.3)
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for credit losses	[1]	$ (1.4)	$ (1.0)	$ (1.1)	$ (1.7)

[1] Operating lease and other trade receivables.