Accounts Payable, Accrued Expenses and Other (Detail) (Truck, Parts and Other, USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Truck, Parts and Other
Accounts Payable and Accrued Liabilities [Line Items]
Accounts payable	$ 1,167.6	$ 1,005.6
Product support reserves	355.3	291.7
Accrued expenses	213.5	234.3
Accrued capital expenditures	63.9	139.9
Salaries and wages	224.9	223.9
Other	272.0	259.6
Accounts payable, accrued expenses and other	$ 2,297.2	$ 2,155.0