Restructuring - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Estimated total cash expenditures for restructuring	$ 7.0
Incurred a total cumulative restructuring charges	6.6
Closure of facility, completion date	Sep. 30, 2010
Severance costs
Restructuring Cost and Reserve [Line Items]
Estimated total cash expenditures for restructuring	2.7
Incurred a total cumulative restructuring charges	2.7
Facility closure costs
Restructuring Cost and Reserve [Line Items]
Estimated total cash expenditures for restructuring	4.3
Incurred a total cumulative restructuring charges	$ 3.9