Summary of Impaired Loans and Specific Reserve (Detail) (Financial Services, USD $) In Millions, unless otherwise specified	6 Months Ended		12 Months Ended
	Jun. 30, 2014		Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Impaired loans with a specific reserve	$ 21.5		$ 22.4
Associated allowance	(3.7)		(4.1)
Net carrying amount of impaired loans	17.8		18.3
Average recorded investment	35.0	[1]	47.6	[2]
Dealer | Wholesale
Financing Receivable, Impaired [Line Items]
Impaired loans with a specific reserve	8.0		8.5
Associated allowance	(1.3)		(1.4)
Net carrying amount of impaired loans	6.7		7.1
Average recorded investment	7.1	[1]	3.6	[2]
Customer Retail | Fleet
Financing Receivable, Impaired [Line Items]
Impaired loans with a specific reserve	10.9		10.8
Associated allowance	(1.8)		(2.1)
Net carrying amount of impaired loans	9.1		8.7
Average recorded investment	24.3	[1]	37.1	[2]
Customer Retail | Owner/Operator
Financing Receivable, Impaired [Line Items]
Impaired loans with a specific reserve	2.6		3.1
Associated allowance	(0.6)		(0.6)
Net carrying amount of impaired loans	2.0		2.5
Average recorded investment	$ 3.6	[1]	$ 6.9	[2]

[1] Represents the average during the 12 months ended June 30, 2014.

[2] Represents the average during the 12 months ended June 30, 2013.