Summary of Impaired Loans and Specific Reserve (Cash Basis Method) (Detail) (Financial Services, USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Interest income recognized:
Interest income recognized on a cash basis	$ 0.6	$ 0.7
Retail \| Fleet
Interest income recognized:
Interest income recognized on a cash basis	0.4	0.4
Retail \| Owner/Operator
Interest income recognized:
Interest income recognized on a cash basis	$ 0.2	$ 0.3

Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)(3)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5212-111524

Name:	us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration