Segment and Related Information - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012 Segment	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Number of operating segments									3
Net sales	$ 217.7	$ 185.0	$ 204.4	$ 196.1	$ 195.0	$ 167.8	$ 175.6	$ 150.3	$ 803.2	$ 688.7	$ 633.1
Outside United States
Segment Reporting Information [Line Items]
Net sales									310.5	268.2	258.5
Exports From U S To Other Regions
Segment Reporting Information [Line Items]
Net sales									$ 127.9	$ 126.1	$ 112.4