Summary of Quarterly Financial Results (Detail) (USD $) In Thousands, except Per Share data, 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	Dec. 31, 2011	Dec. 31, 2010
Net sales	$ 90,468	$ 94,167	$ 97,535	$ 96,754	$ 89,343	$ 93,741	$ 98,831	$ 101,673	$ 378,924	$ 383,588	$ 316,113
Gross profit	17,304	19,269	21,993	19,241	16,932	14,512	18,057	18,005	77,807	67,506	53,863
Income from continuing operations	2,427	3,875	6,592	3,912	2,668	1,131	2,616	2,632	21,378	16,188	3,515
Net income	$ 2,427	$ 3,875	$ 6,592	$ 3,912	$ 2,668	$ 1,131	$ 7,100	$ 2,880	$ 16,806	$ 13,779	$ 2,639
Basic earnings per share:
Continuing operations	$ 0.15	$ 0.23	$ 0.39	$ 0.23	$ 0.16	$ 0.07	$ 0.16	$ 0.16	$ 1.01	$ 0.54	$ 0.11
Net income	$ 0.15	$ 0.23	$ 0.39	$ 0.23	$ 0.16	$ 0.07	$ 0.42	$ 0.17	$ 1.01	$ 0.82	$ 0.16
Diluted earnings per share:
Continuing operations	$ 0.14	$ 0.23	$ 0.39	$ 0.23	$ 0.16	$ 0.07	$ 0.15	$ 0.16	$ 0.99	$ 0.54	$ 0.11
Net income	$ 0.14	$ 0.23	$ 0.39	$ 0.23	$ 0.16	$ 0.07	$ 0.42	$ 0.17	$ 0.99	$ 0.82	$ 0.16