Changes in Accumulated Other Comprehensive Income Before Tax from Continuing Operations (Detail) - Pension Plans, Defined Benefit - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Total retirement benefit recognized in accumulated other comprehensive income at beginning of year	$ 56.3	$ 95.9
Net actuarial (gain) loss	(6.0)	(33.4)
Amortization of prior service credit (cost)	0.0	(0.2)
Amortization of actuarial loss	(2.2)	(6.0)
Total retirement benefit recognized in accumulated other comprehensive income at end of year	48.1	56.3
Non-U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Total retirement benefit recognized in accumulated other comprehensive income at beginning of year	35.5	32.2
Net actuarial (gain) loss	1.6	2.4
Amortization of prior service credit (cost)	(0.3)	(0.2)
Amortization of actuarial loss	(1.5)	(2.0)
Translation difference	(1.4)	3.1
Total retirement benefit recognized in accumulated other comprehensive income at end of year	$ 33.9	$ 35.5