Changes in Product Support Liabilities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
WARRANTY RESERVES
Beginning balance	$ 380.2
Ending balance	440.0	$ 380.2
Truck, Parts and Other
WARRANTY RESERVES
Beginning balance	380.2	298.8	$ 282.1
Cost accruals	386.3	331.9	242.1
Payments	(343.7)	(271.8)	(236.8)
Change in estimates for pre-existing warranties	19.8	25.6	(2.0)
Currency translation and other	(2.6)	(4.3)	13.4
Ending balance	440.0	380.2	298.8
DEFERRED REVENUES ON EXTENDED WARRANTIES AND R&M CONTRACTS
Beginning balance	699.9	653.9	573.5
Deferred revenues	499.1	448.2	371.8
Revenues recognized	(396.4)	(385.0)	(328.2)
Currency translation	(1.2)	(17.2)	36.8
Ending balance	$ 801.4	$ 699.9	$ 653.9