Schedule of Changes in Balance Sheet Position of Restructuring Reserves (Detail) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	$ 81.9	$ 79.3	$ 79.8	$ 94.2
Provision/ Charge	41.1	7.6	35.6	42.8
Provision/ Reversal	(0.1)	(0.9)	(0.9)	(2.3)
Cash payments	(12.5)	(6.9)	(26.2)	(44.5)
Translation difference	(0.5)	2.8	(9.0)	(10.4)
Restructuring reserve, ending balance	109.9	81.9	79.3	79.8
Restructuring employee-related
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	81.9	79.3	79.6	93.9
Provision/ Charge	41.1	7.4	35.5	42.6
Provision/ Reversal	(0.1)	(0.9)	(0.9)	(2.3)
Cash payments	(12.5)	(6.7)	(25.9)	(44.2)
Translation difference	(0.5)	2.8	(9.0)	(10.4)
Restructuring reserve, ending balance	$ 109.9	81.9	79.3	79.6
Other Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance			0.2	0.3
Provision/ Charge		0.2	0.1	0.2
Provision/ Reversal				0.0
Cash payments		$ (0.2)	$ (0.3)	(0.3)
Translation difference				0.0
Restructuring reserve, ending balance				$ 0.2