Summary of Impaired Loans and Specific Reserve (Cash Basis Method) (Detail) (Financial Services, USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Interest income recognized:
Interest income recognized on a cash basis	$ 0.5	$ 0.4	$ 2.3	$ 1.6
Dealer wholesale financing
Interest income recognized:
Interest income recognized on a cash basis			0.1	0.1
Retail | Fleet
Interest income recognized:
Interest income recognized on a cash basis	0.5	0.2	1.8	0.9
Retail | Owner/Operator
Interest income recognized:
Interest income recognized on a cash basis		$ 0.2	$ 0.4	$ 0.6