Allowance for Credit Losses (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		$ 65.7	$ 68.2
Provision for losses on receivables		(2.5)	0.6
Charge-offs		(0.2)	(0.7)
Recoveries		0.7	0.5
Ending Balance		63.7	68.6
Dealer | Wholesale
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		1.0	1.3
Provision for losses on receivables		0.1
Ending Balance		1.1	1.3
Dealer | Retail
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		6.5	7.5
Provision for losses on receivables		(1.9)	(0.2)
Ending Balance		4.6	7.3
Customer Retail
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		57.1	57.7
Provision for losses on receivables		(0.5)	0.7
Charge-offs		(0.2)	(0.7)
Recoveries		0.7	0.5
Ending Balance		57.1	58.2
Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	[1]	1.1	1.7
Provision for losses on receivables	[1]	(0.2)	0.1
Ending Balance	[1]	$ 0.9	$ 1.8

[1] Operating lease and other trade receivables