Changes in Product Support Liabilities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
WARRANTY RESERVES
Beginning balance	$ 767.0
Ending balance	606.1	$ 767.0
DEFERRED REVENUES ON EXTENDED WARRANTIES AND R&M CONTRACTS
Beginning balance	1,229.1	904.9	$ 775.2
Deferred revenues	701.1	812.4	629.1
Revenues recognized	(591.8)	(507.8)	(476.1)
Currency translation	(36.2)	19.6	(23.3)
Ending balance	1,302.2	1,229.1	904.9
Truck, Parts and Other
WARRANTY RESERVES
Beginning balance	767.0	437.7	344.3
Cost accruals	616.2	739.2	386.1
Payments	(917.8)	(632.4)	(398.7)
Change in estimates for pre-existing warranties	163.2	211.9	111.5
Currency translation and other	(22.5)	10.6	(5.5)
Ending balance	$ 606.1	$ 767.0	$ 437.7