Allowance for Credit Losses (Detail) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2020		Sep. 30, 2019
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for losses		$ 27.6		$ 11.8
Dealer | Wholesale
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		4.3
Ending Balance		3.2
Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		3.7
Ending Balance		3.7
Financial Services
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		118.6	[1]	113.8
Provision for losses		27.6	[1]	11.8
Charge-offs		(23.5)	[1]	(18.5)
Recoveries		4.0	[1]	8.9
Currency translation and other		(2.0)	[1]	(1.1)
Ending Balance		124.7	[1]	114.9
Financial Services | Dealer | Wholesale
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		4.3		6.8
Provision for losses		(1.1)
Charge-offs				(0.2)
Currency translation and other				(0.2)
Ending Balance		3.2		6.4
Financial Services | Dealer | Retail
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		9.2		10.0
Provision for losses		(0.8)		(0.9)
Currency translation and other				0.2
Ending Balance		8.4		9.3
Financial Services | Customer Retail
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		101.4		93.8
Provision for losses		28.5		9.7
Charge-offs		(22.3)		(15.6)
Recoveries		3.6		8.8
Currency translation and other		(1.8)		(1.0)
Ending Balance		109.4		95.7
Financial Services | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	[2]	3.7		3.2
Provision for losses	[2]	1.0		3.0
Charge-offs	[2]	(1.2)		(2.7)
Recoveries	[2]	0.4		0.1
Currency translation and other	[2]	(0.2)		(0.1)
Ending Balance	[2]	$ 3.7		$ 3.5

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

[2] Operating leases and other trade receivables.