Retirement Benefit Plan - Summary of Amounts Recognized in Balance Sheet (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
U.S. and Puerto Rico [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Prepaid pension		$ 22.8
Short-term accrued benefit liability	$ (0.2)	(5.6)
Long-term accrued benefit liability	(7.3)	(4.3)
Net amount recognized	(7.5)	12.9
Foreign [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Prepaid pension	15.3	14.9
Short-term accrued benefit liability	(0.8)	(0.8)
Long-term accrued benefit liability	(59.8)	(62.8)
Net amount recognized	$ (45.3)	$ (48.7)