Changes in Product Support Liabilities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
WARRANTY RESERVES
Beginning balance	$ 437.7
Ending balance	767.0	$ 437.7
Truck, Parts and Other
WARRANTY RESERVES
Beginning balance	437.7	344.3	$ 389.7
Cost accruals	739.2	386.1	298.2
Payments	(632.4)	(398.7)	(396.3)
Change in estimates for pre-existing warranties	211.9	111.5	58.3
Currency translation and other	10.6	(5.5)	(5.6)
Ending balance	767.0	437.7	344.3
DEFERRED REVENUES ON EXTENDED WARRANTIES AND R&M CONTRACTS
Beginning balance	904.9	775.2	795.8
Deferred revenues	812.4	629.1	487.1
Revenues recognized	(507.8)	(476.1)	(487.8)
Currency translation	19.6	(23.3)	(19.9)
Ending balance	$ 1,229.1	$ 904.9	$ 775.2