Changes in Product Support Liabilities (Detail) - Truck, Parts and Other - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
WARRANTY RESERVES
Beginning balance	$ 767.0	$ 437.7
Cost accruals	181.3	163.8
Payments	(220.8)	(134.3)
Change in estimates for pre-existing warranties	41.8	53.1
Currency translation and other	(5.9)	3.3
Ending balance	763.4	523.6
DEFERRED REVENUES ON EXTENDED WARRANTIES AND R&M CONTRACTS
Beginning balance	1,229.1	904.9
Deferred revenues	177.7	208.6
Revenues recognized	(141.4)	(119.3)
Currency translation	(11.8)	7.0
Ending balance	$ 1,253.6	$ 1,001.2