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
	Mar. 31, 2014	Mar. 31, 2013
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Investment	$ 5.9	$ 4.7
Post-Modification Recorded Investment	5.9	4.6
Customer Retail | Fleet
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Investment	4.9	4.2
Post-Modification Recorded Investment	4.9	4.1
Customer Retail | Owner/Operator
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Investment	1.0	0.5
Post-Modification Recorded Investment	$ 1.0	$ 0.5