Schedule of Reserve Activity for Closures and Consolidation (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
2012 Exit Activity | Lease Termination
Restructuring Cost and Reserve [Line Items]
Charge	$ 0.9
Cash expenditures	(0.3)
Ending balance	0.6
2012 Exit Activity | Severance
Restructuring Cost and Reserve [Line Items]
Charge	0.1
Cash expenditures	(0.1)
2011 Exit Activity | Lease Termination
Restructuring Cost and Reserve [Line Items]
Beginning balance	2.7
Charge	0.1	3.0
Cash expenditures	(2.5)	(0.3)
Ending balance	0.3	2.7
2011 Exit Activity | Severance
Restructuring Cost and Reserve [Line Items]
Beginning balance	0.1
Charge		0.7
Cash expenditures	(0.1)	(0.6)
Ending balance		0.1
2010 Exit Activity | Lease Termination
Restructuring Cost and Reserve [Line Items]
Beginning balance	5.0	7.6
Charge		0.8	10.2
Cash expenditures	(4.7)	(3.4)	(2.6)
Ending balance	0.3	5.0	7.6
2010 Exit Activity | Severance
Restructuring Cost and Reserve [Line Items]
Beginning balance		0.2
Charge			0.7
Cash expenditures		(0.2)	(0.5)
Ending balance			$ 0.2