Allowance for Credit Losses (Detail) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for losses		$ 3.2	$ 24.5
Dealer | Wholesale
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		3.4
Ending Balance		3.4
Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		3.2
Ending Balance		3.6
Financial Services
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		127.0	118.6	[1]
Provision for losses		3.2	24.5	[1]
Charge-offs		(7.5)	(18.5)	[1]
Recoveries		3.0	2.5	[1]
Currency translation and other		(0.4)	(3.6)	[1]
Ending Balance		125.3	123.5	[1]
Financial Services | Dealer | Wholesale
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		3.4	4.3
Provision for losses			(0.7)
Currency translation and other			(0.1)
Ending Balance		3.4	3.5
Financial Services | Dealer | Retail
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		8.4	9.2
Provision for losses		(0.3)	(0.2)
Currency translation and other			(0.1)
Ending Balance		8.1	8.9
Financial Services | Customer Retail
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		112.0	101.4
Provision for losses		2.7	23.9
Charge-offs		(6.9)	(17.7)
Recoveries		2.8	2.2
Currency translation and other		(0.4)	(3.2)
Ending Balance		110.2	106.6
Financial Services | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	[2]	3.2	3.7
Provision for losses	[2]	0.8	1.5
Charge-offs	[2]	(0.6)	(0.8)
Recoveries	[2]	0.2	0.3
Currency translation and other	[2]		(0.2)
Ending Balance	[2]	$ 3.6	$ 4.5

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

[2] Operating leases and other trade receivables.