Finance and Other Receivables (Detail) - USD ($) $ in Millions		Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023
Financial Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		$ 9,579.2	$ 9,442.4
Finance leases		5,051.5	4,906.6
Dealer wholesale financing		4,947.3	4,944.1
Operating lease receivables and other		177.9	166.4
Finance and other receivables, net of deferred income		19,755.9	19,459.5
Less allowance for losses		(144.6)	(145.2)	$ (139.3)	$ (133.0)
Finance and other receivables, net		19,611.3	19,314.3
Loans and Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for losses		(138.7)	(139.2)
Dealer | Wholesale
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for losses		(3.0)	(3.0)
Dealer | Wholesale | Financial Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for losses		(3.0)	(3.0)	(2.7)	(2.7)
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for losses		(2.9)	(3.0)
Other | Financial Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for losses	[1]	$ (2.9)	$ (3.0)	$ (3.3)	$ (3.3)

[1] Operating leases and other trade receivables.