Components of Accumulated Other Comprehensive Income Before Tax Related to Continuing Operations (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Plans, Defined Benefit | U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	$ 48.0	$ 56.2
Prior service cost	0.1	0.1
Total accumulated other comprehensive income recognized in the balance sheet	48.1	56.3	$ 95.9
Pension Plans, Defined Benefit | Non-U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	30.8	32.6
Prior service cost	3.1	2.9
Total accumulated other comprehensive income recognized in the balance sheet	33.9	35.5	$ 32.2
Postretirement Benefits Other Than Pensions | U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	(4.6)	(3.7)
Prior service cost	(8.2)	(10.6)
Total accumulated other comprehensive income recognized in the balance sheet	$ (12.8)	$ (14.3)