Retirement Benefit Plans - Plans with Benefit Obligations in Excess of Plan Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
U.S. and Puerto Rico [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Projected benefit obligation	$ 516.9	$ 472.0
Plan assets at fair market value	474.1	444.9
Foreign [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Projected benefit obligation	778.4	698.2
Plan assets at fair market value	$ 709.5	$ 619.1