Financing Receivables by Aging Category (Detail) - Financial Services - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, current and up to 30 days past due	$ 8,874.7	$ 8,759.2
Financing Receivables	8,922.1	8,797.7
31 - 60 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, past due	19.4	16.5
Greater than 60 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, past due	28.0	22.0
Dealer \| Wholesale
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, current and up to 30 days past due	1,624.4	1,528.4
Financing Receivables	1,625.1	1,528.5
Dealer \| Wholesale \| 31 - 60 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, past due	0.6	0.0
Dealer \| Wholesale \| Greater than 60 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, past due	0.1	0.1
Dealer \| Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, current and up to 30 days past due	1,339.6	1,406.0
Financing Receivables	1,343.7	1,406.0
Dealer \| Retail \| 31 - 60 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, past due	0.0	0.0
Dealer \| Retail \| Greater than 60 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, past due	4.1	0.0
Customer Retail \| Fleet
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, current and up to 30 days past due	4,923.2	4,898.4
Financing Receivables	4,955.0	4,928.7
Customer Retail \| Fleet \| 31 - 60 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, past due	12.5	12.6
Customer Retail \| Fleet \| Greater than 60 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, past due	19.3	17.7
Customer Retail \| Owner/Operator
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, current and up to 30 days past due	987.5	926.4
Financing Receivables	998.3	934.5
Customer Retail \| Owner/Operator \| 31 - 60 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, past due	6.3	3.9
Customer Retail \| Owner/Operator \| Greater than 60 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables, past due	$ 4.5	$ 4.2

Financing receivables that are current.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953401-111524

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- Definition

Recorded Investment in financing receivables that are past due at the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953401-111524

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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.

+ References

No definition available.

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- Definition

Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(3))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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