Accounts Payable, Accrued Expenses and Other (Detail) - Truck, Parts and Other - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounts Payable and Accrued Liabilities [Line Items]
Accounts payable	$ 1,176.2	$ 1,115.7
Product support liabilities	514.6	508.1
Accrued expenses	446.5	467.4
Right-of-return liabilities	337.3	226.0
Accrued capital expenditures	288.8	270.3
Salaries and wages	260.8	271.8
Other	389.7	334.9
Accounts payable, accrued expenses and other	$ 3,413.9	$ 3,194.2