Retirement Benefit Plans - Changes in Projected Benefit Obligations and Plan Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S. and Puerto Rico [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Projected benefit obligation - beginning of year	$ 376.9	$ 375.1
Service cost	8.7	9.6	$ 11.8
Interest cost	14.0	13.8	15.8
Benefits paid	(14.9)	(14.3)
Actuarial loss (gain)	36.9	(1.6)
Settlement	(0.9)	(5.7)
Projected benefit obligation - end of year	420.7	376.9	375.1
Foreign-based Defined Benefit Plans [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Projected benefit obligation - beginning of year	568.6	568.6
Service cost	17.7	19.0	18.9
Interest cost	8.4	10.0	8.8
Plan amendments	0.6	(23.4)
Employee contributions	17.0	23.6
Benefits paid	(34.5)	(31.6)
Actuarial loss (gain)	15.6	46.7
Expenses paid	(0.2)	(0.2)
Settlement	(0.8)
Translation gain (loss)	31.2	(44.1)
Projected benefit obligation - end of year	$ 623.6	$ 568.6	$ 568.6