Property, Plant and Equipment (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 3,780.1	$ 3,468.4	$ 3,398.1
Truck, Parts and Other
Property, Plant and Equipment [Line Items]
Land	325.7	269.9
Buildings and improvements	1,703.8	1,608.6
Machinery, equipment and production tooling	5,337.7	5,086.6
Construction in progress	676.3	424.1
Property, Plant and Equipment, Gross, Total	8,043.5	7,389.2
Less allowance for depreciation	(4,263.4)	(3,920.8)
Property, plant and equipment, net	$ 3,780.1	$ 3,468.4
Truck, Parts and Other | Minimum | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Truck, Parts and Other | Minimum | Machinery Equipment And Production Tooling
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Truck, Parts and Other | Maximum | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	40 years
Truck, Parts and Other | Maximum | Machinery Equipment And Production Tooling
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	20 years