Pre- and Post-Modification Recorded Investment Balances for Finance Receivables Modified by Portfolio Class (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
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Investment	$ 2.2	$ 15.3	$ 10.6	$ 47.4
Post-Modification Recorded Investment	2.0	14.5	10.3	45.9
Retail | Fleet
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Investment	1.5	14.7	9.2	45.3
Post-Modification Recorded Investment	1.3	13.9	8.9	43.8
Retail | Owner/Operator
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Investment	0.7	0.6	1.4	2.1
Post-Modification Recorded Investment	$ 0.7	$ 0.6	$ 1.4	$ 2.1