Allowance for Credit Losses (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for losses on financial services receivables		$ 22.3	$ 18.4	$ 12.4
Dealer | Wholesale
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		5.5
Ending Balance		6.0	5.5
Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		8.6
Ending Balance		9.3	8.6
Financial Services
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		111.2	114.8	122.0
Provision for losses on financial services receivables		22.3	18.4	12.4
Charge-offs		(26.7)	(25.0)	(17.1)
Recoveries		5.3	5.8	4.0
Currency translation and other		5.1	(2.8)	(6.5)
Ending Balance		117.2	111.2	114.8
Financial Services | Dealer | Wholesale
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		5.5	7.3	9.0
Provision for losses on financial services receivables			(1.7)	(0.8)
Charge-offs			0.0	(0.3)
Recoveries			0.0	0.0
Currency translation and other		0.5	(0.1)	(0.6)
Ending Balance		6.0	5.5	7.3
Financial Services | Dealer | Retail
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		9.6	10.3	11.9
Provision for losses on financial services receivables		(0.3)	(0.7)	(1.4)
Charge-offs			0.0	0.0
Recoveries			0.0	0.0
Currency translation and other		0.1	0.0	(0.2)
Ending Balance		9.4	9.6	10.3
Financial Services | Customer Retail
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance		87.5	88.9	93.6
Provision for losses on financial services receivables		21.1	18.6	11.6
Charge-offs		(24.8)	(22.9)	(13.6)
Recoveries		5.0	5.5	3.5
Currency translation and other		3.7	(2.6)	(6.2)
Ending Balance		92.5	87.5	88.9
Financial Services | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	[1]	8.6	8.3	7.5
Provision for losses on financial services receivables	[1]	1.5	2.2	3.0
Charge-offs	[1]	(1.9)	(2.1)	(3.2)
Recoveries	[1]	0.3	0.3	0.5
Currency translation and other	[1]	0.8	(0.1)	0.5
Ending Balance	[1]	$ 9.3	$ 8.6	$ 8.3

[1] Operating lease and other trade receivables.