Allowance for Credit Losses (Detail) (Financial Services, USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	$ 130.0		$ 139.0
Provision for losses	6.5		7.5
Charge-offs	(5.1)		(8.8)
Recoveries	1.6		1.4
Currency translation and other	(0.1)		2.2
Ending Balance	132.9		141.3
Dealer wholesale financing
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	11.8		11.7
Provision for losses	0.3		2.7
Charge-offs	(0.1)
Currency translation and other	(0.2)		0.2
Ending Balance	11.8		14.6
Retail | Customer
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	99.2		106.5
Provision for losses	5.5		3.4
Charge-offs	(4.6)		(6.7)
Recoveries	1.4		1.3
Currency translation and other	0.4		2.0
Ending Balance	101.9		106.5
Retail | Dealer
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	13.4		12.0
Provision for losses	(0.8)		0.1
Currency translation and other	(0.1)
Ending Balance	12.5		12.1
Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	5.6	[1]	8.8	[1]
Provision for losses	1.5	[1]	1.3	[1]
Charge-offs	(0.4)	[1]	(2.1)	[1]
Recoveries	0.2	[1]	0.1	[1]
Currency translation and other	(0.2)	[1]
Ending Balance	$ 6.7	[1]	$ 8.1	[1]

[1] Operating lease and other trade receivables.