Summary of Impaired Loans and Specific Reserve (Cash Basis Method) (Detail) - Financial Services - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Interest income recognized:
Interest income recognized on a cash basis	$ 0.5	$ 0.4	$ 1.3	$ 1.3
Dealer | Wholesale
Interest income recognized:
Interest income recognized on a cash basis				0.1
Customer Retail | Fleet
Interest income recognized:
Interest income recognized on a cash basis	0.4	0.3	1.0	0.9
Customer Retail | Owner/Operator
Interest income recognized:
Interest income recognized on a cash basis	$ 0.1	$ 0.1	$ 0.3	$ 0.3