Retirement Benefit Plans - Changes in Projected Benefit Obligations and Plan Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
U.S. and Puerto Rico [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Projected benefit obligation - beginning of year	$ 472.0	$ 396.0
Service cost	0.7	7.1	$ 8.0
Interest cost	13.9	16.2	14.2
Plan amendments		3.6
Benefits paid	(24.0)	(16.9)
Actuarial loss	55.6	68.2
Settlement	(1.3)	(2.2)
Projected benefit obligation - end of year	516.9	472.0	396.0
Foreign [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Projected benefit obligation - beginning of year	740.4	631.1
Service cost	24.7	19.0	20.0
Interest cost	5.4	9.0	8.1
Plan amendments	0.2
Employee contributions	22.1	20.6
Benefits paid	(39.8)	(36.5)
Actuarial loss	12.5	77.8
Expenses paid	(0.3)	(0.3)
Settlement	(4.5)
Translation loss	58.6	19.7
Projected benefit obligation - end of year	$ 819.3	$ 740.4	$ 631.1