Summary of Impaired Loans and Specific Reserve (Detail) (Financial Services, USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2014		Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Impaired loans with a specific reserve	$ 21.9		$ 22.4
Associated allowance	(3.8)		(4.1)
Net carrying amount of impaired loans	18.1		18.3
Average recorded investment	38.2	[1]	53.7	[2]
Dealer | Wholesale
Financing Receivable, Impaired [Line Items]
Impaired loans with a specific reserve	6.5		8.5
Associated allowance	(1.3)		(1.4)
Net carrying amount of impaired loans	5.2		7.1
Average recorded investment	6.2	[1]	6.3	[2]
Customer Retail | Fleet
Financing Receivable, Impaired [Line Items]
Impaired loans with a specific reserve	12.5		10.8
Associated allowance	(1.9)		(2.1)
Net carrying amount of impaired loans	10.6		8.7
Average recorded investment	27.7	[1]	39.3	[2]
Customer Retail | Owner/Operator
Financing Receivable, Impaired [Line Items]
Impaired loans with a specific reserve	2.9		3.1
Associated allowance	(0.6)		(0.6)
Net carrying amount of impaired loans	2.3		2.5
Average recorded investment	$ 4.3	[1]	$ 8.1	[2]

[1] Represents the average during the 12 months ended March 31, 2014.

[2] Represents the average during the 12 months ended March 31, 2013.