Retirement Benefit Plans - Plans with Benefit Obligations in Excess of Plan Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
U.S. and Puerto Rico [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Projected benefit obligation	$ 55.1	$ 51.3
Plan assets at fair market value	45.2	39.8
Foreign-based Defined Benefit Plans [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Projected benefit obligation	598.8	545.7
Plan assets at fair market value	$ 544.2	$ 480.2