Summary of Impaired Loans and Specific Reserve (Cash Basis Method) (Detail) (Financial Services, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Interest income recognized:
Interest income recognized on a cash basis	$ 3.9	$ 2.1	$ 5.1
Dealer wholesale financing
Interest income recognized:
Interest income recognized on a cash basis	0.1	0.1	0.4
Retail | Fleet
Interest income recognized:
Interest income recognized on a cash basis	2.9	1.2	2.7
Retail | Owner/operator
Interest income recognized:
Interest income recognized on a cash basis	$ 0.9	$ 0.8	$ 2.0