Profit Sharing, Retirement Savings Plans and Defined Benefit Pension Plans - Amounts in Accumulated Other Comprehensive Loss, Not Yet Recognized (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Unrecognized prior service costs	$ 0.7	$ (1.2)
Unrecognized net actuarial loss	146.1	205.0
Total	146.8	203.8
U.S.
Defined Benefit Plan Disclosure [Line Items]
Unrecognized prior service costs	0.1	0.0
Unrecognized net actuarial loss	41.4	42.0
Total	41.5	42.0
International
Defined Benefit Plan Disclosure [Line Items]
Unrecognized prior service costs	0.6	(1.2)
Unrecognized net actuarial loss	104.7	163.0
Total	$ 105.3	$ 161.8