Pre- and Post-Modification Recorded Investment Balances for Finance Receivables Modified by Portfolio Class (Detail) - Financial Services - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Investment	$ 20.5	$ 31.6
Post-Modification Recorded Investment	20.5	31.6
Customer Retail \| Fleet
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Investment	19.9	27.2
Post-Modification Recorded Investment	19.9	27.2
Customer Retail \| Owner/Operator
Financing Receivable, Modifications [Line Items]
Pre-Modification Recorded Investment	0.6	4.4
Post-Modification Recorded Investment	$ 0.6	$ 4.4

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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- Definition

Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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- Definition

Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

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