Changes in Product Support Liabilities (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
WARRANTY RESERVES
Beginning balance	$ 282.1
Ending balance	298.8	$ 282.1
DEFERRED REVENUES ON EXTENDED WARRANTIES AND R&M CONTRACTS
Beginning balance	573.5
Ending balance	653.9	573.5
Truck, Parts and Other
WARRANTY RESERVES
Beginning balance	282.1	346.2	$ 310.8
Cost accruals	242.1	211.9	294.8
Payments	(236.8)	(255.7)	(228.8)
Change in estimates for pre-existing warranties	(2.0)	(7.3)	(21.3)
Currency translation	13.4	(13.0)	(9.3)
Ending balance	298.8	282.1	346.2
DEFERRED REVENUES ON EXTENDED WARRANTIES AND R&M CONTRACTS
Beginning balance	573.5	524.8	462.0
Deferred revenues	371.8	347.6	333.0
Revenues recognized	(328.2)	(274.3)	(248.4)
Currency translation	36.8	(24.6)	(21.8)
Ending balance	$ 653.9	$ 573.5	$ 524.8

Deferred revenue, currency translation, increase (decrease).

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- Definition

Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 13.A.3)
-URI http://asc.fasb.org/extlink&oid=65893310&loc=d3e214044-122780

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-Subparagraph (SAB Topic 13.A.4(a).Q1)
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- Definition

Amount of deferred revenue recognized for transactions arising during the current reporting period. Deferred revenue is a liability as of the balance sheet date related to a revenue producing activity for which revenue has not yet been recognized. Generally, an Entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 13.A.4(a).Q1)
-URI http://asc.fasb.org/extlink&oid=65893310&loc=d3e214044-122780

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
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-Section S99
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- Definition

Amount of revenue recognized that was previously reported as deferred or unearned revenue.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount as of the balance sheet date of the aggregate standard product warranty liability. Does not include the balance for the extended product warranty liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)(1),(c)(5)
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- Definition

Amount of foreign currency translation gain (loss) which decreases (increases) the standard product warranty accrual. Excludes extended product warranties.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=68068213&loc=d3e12565-110249

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- Definition

Amount of decrease in the standard product warranty accrual from payments made in cash or in kind to satisfy claims under the terms of the standard product warranty. Excludes extended product warranties.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 8
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- Definition

Amount of increase (decrease) in the standard product warranty accrual from changes in estimates attributable to preexisting product warranties. Excludes extended product warranties.

+ References

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-Paragraph 8
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- Definition

Amount of increase in the standard product warranty accrual from warranties issued. Excludes extended product warranties.

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