Estimated Value of Returned Goods Assets and Related Return Liabilities (Detail) - Truck, Parts and Other - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Trucks
Entity Wide Information Revenue From External Customer [Line Items]
Other current assets	$ 165.8	$ 183.0
Accounts payable, accrued expenses and other	166.6	185.0
Other noncurrent assets, net	201.8	284.6
Other liabilities	211.9	298.9
Assets	367.6	467.6
Liabilities	378.5	483.9
Parts Subsegment
Entity Wide Information Revenue From External Customer [Line Items]
Accounts payable, accrued expenses and other	208.6	181.4
Other noncurrent assets, net	81.8	77.7
Assets	81.8	77.7
Liabilities	$ 208.6	$ 181.4