Finance and Other Receivables (Detail) - USD ($) $ in Millions		Mar. 31, 2022	Dec. 31, 2021		Mar. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retail loans		$ 4,374.2	$ 4,300.5
Retail financing leases		1,362.4	1,381.9
Dealer wholesale financing		762.1	737.6
Dealer master notes		405.3	322.7
Operating lease receivables and other		54.2	51.4
Total portfolio		6,958.2	6,794.1
Less allowance for credit losses		(63.7)	(65.7)		$ (68.6)	$ (68.2)
Finance and other receivables, net		6,894.5	6,728.4	[1]
Loans and Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for credit losses		(61.7)	(63.6)
Dealer | Wholesale
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for credit losses		(1.1)	(1.0)		(1.3)	(1.3)
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for credit losses	[2]	$ (0.9)	$ (1.1)		$ (1.8)	$ (1.7)

[1] The December 31, 2021 balance sheet has been derived from audited financial statements.

[2] Operating lease and other trade receivables