Schedule of Changes in Balance Sheet Position of Restructuring Reserves (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	$ 30.8	$ 87.0	$ 37.5	$ 87.9
Provision/ Charge	1.3	3.7	3.8	17.3
Provision/ Reversal	(3.7)	(0.3)	(4.2)	(0.7)
Cash payments	(5.4)	(21.5)	(14.7)	(39.1)
Translation difference	1.7	(2.3)	2.3	1.2
Restructuring reserve, ending balance	24.7	66.6	24.7	66.6
Restructuring employee-related
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	30.6	86.8	37.1	87.7
Provision/ Charge	1.3	3.7	3.6	17.3
Provision/ Reversal	(3.7)	(0.3)	(3.8)	(0.7)
Cash payments	(5.4)	(21.5)	(14.7)	(39.1)
Translation difference	1.7	(2.2)	2.3	1.3
Restructuring reserve, ending balance	24.5	66.5	24.5	66.5
Other Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	0.2	0.2	0.4	0.2
Provision/ Charge	0.0		0.2
Provision/ Reversal	0.0		(0.4)
Cash payments	0.0		0.0
Translation difference	0.0	(0.1)	0.0	(0.1)
Restructuring reserve, ending balance	$ 0.2	$ 0.1	$ 0.2	$ 0.1