Schedule of Changes in Balance Sheet Position of Restructuring Reserves (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	$ 39.6	$ 35.8	$ 87.1
Provision/ Charge	9.2	29.5	23.7
Provision/ Reversal	(0.1)	(6.9)	(2.6)
Cash payments	(13.6)	(23.3)	(71.3)
Translation difference	(1.7)	4.5	(1.1)
Restructuring reserve, ending balance	33.4	39.6	35.8
Restructuring employee-related
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	39.4	35.7	86.9
Provision/ Charge	9.0	29.3	23.6
Provision/ Reversal	(0.1)	(6.9)	(2.6)
Cash payments	(13.6)	(23.3)	(71.3)
Translation difference	(1.5)	4.6	(0.9)
Restructuring reserve, ending balance	33.2	39.4	35.7
Other Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	0.2	0.1	0.2
Provision/ Charge	0.2	0.2	0.1
Translation difference	(0.2)	(0.1)	(0.2)
Restructuring reserve, ending balance	$ 0.2	$ 0.2	$ 0.1