Pension and Other Postretirement Benefit Plans - Components of Net Periodic Benefit Costs (Credit) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension | U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Service cost	$ 0.1	$ 0.1	$ 0.1
Interest cost	19.8	21.8	29.8
Expected return on plan assets	(27.3)	(24.0)	(32.6)
Amortization of actuarial (gain) loss	2.0	2.6	2.7
Curtailment loss	0.0	0.0	0.0
Settlement loss	5.7	0.2	34.4
Net periodic benefit cost (credit)	0.3	0.7	34.4
Pension | Foreign
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Service cost	6.9	7.3	6.5
Interest cost	14.7	15.0	15.8
Expected return on plan assets	(23.0)	(22.9)	(23.2)
Amortization of actuarial (gain) loss	6.2	5.1	3.1
Curtailment loss	0.4	0.9	0.0
Settlement loss	0.0	0.8	0.4
Net periodic benefit cost (credit)	5.2	6.2	2.6
Other Postretirement | U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Service cost	0.0	0.1	0.2
Interest cost	1.9	2.4	3.2
Amortization of actuarial (gain) loss	(2.2)	(2.6)	(1.3)
Amortization of prior service credit	(0.2)	0.0	0.0
Special termination benefits	0.0	0.0	0.0
Net periodic benefit cost (credit)	(0.5)	(0.1)	2.1
Other Postretirement | Foreign
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Service cost	0.4	0.5	0.5
Interest cost	1.4	1.5	1.6
Amortization of actuarial (gain) loss	0.2	0.3	0.2
Amortization of prior service credit	(0.3)	(0.4)	(0.3)
Special termination benefits	0.0	0.1	0.3
Net periodic benefit cost (credit)	$ 1.7	$ 2.0	$ 2.3