Schedule of Change in Balance Sheet Position of Restructuring Reserves (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	$ 75.8	$ 32.3
Provision/ Charge	2.3	76.9
Provision/ Reversal	(0.1)	(2.1)
Cash payments	(5.1)	(33.3)
Translation difference	(2.3)	2.0
Restructuring reserve, ending balance	70.6	75.8
Restructuring employee-related
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	74.9	31.4
Provision/ Charge	2.3	76.6
Provision/ Reversal	(0.1)	(1.8)
Cash payments	(4.7)	(33.3)
Translation difference	(2.3)	2.0
Restructuring reserve, ending balance	70.1	74.9
Other Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	0.9	0.9
Provision/ Charge		0.3
Provision/ Reversal		(0.3)
Cash payments	(0.4)	0
Translation difference	0
Restructuring reserve, ending balance	$ 0.5	$ 0.9