Allowance for Credit Losses (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for losses		$ 3.7	$ 17.0
Dealer | Wholesale
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		3.4
Ending Balance		3.5
Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		3.2
Ending Balance		3.4
Financial Services
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		127.0	118.6	[1]
Provision for losses		3.7	17.0	[1]
Charge-offs		(4.0)	(10.7)	[1]
Recoveries		1.5	1.5	[1]
Currency translation and other		(1.4)	(5.3)	[1]
Ending Balance		126.8	121.1	[1]
Financial Services | Dealer | Wholesale
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		3.4	4.3
Provision for losses		0.1	0.2
Currency translation and other			(0.2)
Ending Balance		3.5	4.3
Financial Services | Dealer | Retail
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		8.4	9.2
Provision for losses		(0.2)	0.1
Currency translation and other			(0.1)
Ending Balance		8.2	9.2
Financial Services | Customer Retail
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		112.0	101.4
Provision for losses		3.3	16.7
Charge-offs		(3.8)	(10.5)
Recoveries		1.5	1.3
Currency translation and other		(1.3)	(4.7)
Ending Balance		111.7	104.2
Financial Services | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	[2]	3.2	3.7
Provision for losses	[2]	0.5
Charge-offs	[2]	(0.2)	(0.2)
Recoveries	[2]		0.2
Currency translation and other	[2]	(0.1)	(0.3)
Ending Balance	[2]	$ 3.4	$ 3.4

[1] The beginning balance has been adjusted for the adoption of ASU 2016-13.

[2] Operating leases and other trade receivables.