Accounts Payable, Accrued Expenses and Other (Detail) - Truck, Parts and Other - USD ($) $ in Millions	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Accounts Payable and Accrued Liabilities [Line Items]
Accounts payable	$ 1,304.9		$ 1,154.7
Product support liabilities	446.7		372.1
Accrued expenses	626.5		401.4
Accrued capital expenditures	98.8		120.1
Salaries and wages	267.7		238.9
Other	283.1		282.3
Accounts payable, accrued expenses and other	$ 3,027.7	$ 2,672.6	$ 2,569.5