Pension and Other Postretirement Benefit Plans - Pretax Amounts Recorded in Accumulated Other Comprehensive Loss That Are Expected To Be Recognized As Components of Net Periodic Benefit Cost in Next Fiscal Year (Detail) $ in Millions	Dec. 31, 2018 USD ($)
Pension | U.S.
Defined Benefit Plan Disclosure [Line Items]
Net unrecognized actuarial gain (loss)	$ (1.8)
Prior service credit	0.0
Pretax amounts recorded in accumulated other comprehensive loss not yet recognized in net periodic benefit cost (credit) in the subsequent year	(1.8)
Pension | Foreign
Defined Benefit Plan Disclosure [Line Items]
Net unrecognized actuarial gain (loss)	5.6
Prior service credit	0.0
Pretax amounts recorded in accumulated other comprehensive loss not yet recognized in net periodic benefit cost (credit) in the subsequent year	5.6
Other Postretirement | U.S.
Defined Benefit Plan Disclosure [Line Items]
Net unrecognized actuarial gain (loss)	2.3
Prior service credit	0.2
Pretax amounts recorded in accumulated other comprehensive loss not yet recognized in net periodic benefit cost (credit) in the subsequent year	2.5
Other Postretirement | Foreign
Defined Benefit Plan Disclosure [Line Items]
Net unrecognized actuarial gain (loss)	0.0
Prior service credit	0.2
Pretax amounts recorded in accumulated other comprehensive loss not yet recognized in net periodic benefit cost (credit) in the subsequent year	$ 0.2