Restructuring Charges - Schedule of Restructuring Activities (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				12 Months Ended		3 Months Ended	12 Months Ended		3 Months Ended	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Lease And Exit Costs [Member]	Mar. 31, 2013 Two Thousand Twelve Restructuring [Member]	Dec. 31, 2012 Two Thousand Twelve Restructuring [Member]		Mar. 31, 2013 Two Thousand Twelve Restructuring [Member] Employee Severance and other Personnel Benefits [Member]	Dec. 31, 2012 Two Thousand Twelve Restructuring [Member] Employee Severance and other Personnel Benefits [Member]		Mar. 31, 2013 Two Thousand Twelve Restructuring [Member] Other Restructuring Costs [Member]	Dec. 31, 2012 Two Thousand Twelve Restructuring [Member] Other Restructuring Costs [Member]
Restructuring Reserve [Roll Forward]
Restructuring cost, beginning balance	$ 19.2		$ 0.3				$ 18.0			$ 0.9
(Income) expense, net	0.2	0	0	0.3	24.1	[1]	(0.5)	18.4	[1]	0.7	2.3	[1]
Restructuring reserve, translation adjustment	(0.6)		0				(0.6)			0
Cash utilized, net	(4.5)		(0.1)	(4.5)	(3.8)		(3.5)			(0.9)
Non utilized, net	0		0				0			0
Restructuring cost, ending balance	$ 14.3		$ 0.2				$ 13.4	$ 18.0		$ 0.7	$ 0.9

[1] Included within the $20.7 million restructuring charges is a net pension curtailment gain of $1.5 million.