Quarterly Financial Information (Unaudited) (Summary of Quarterly Financial Results) (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 127,583	$ 134,227	$ 148,793	$ 125,226	$ 99,894	$ 97,995	$ 101,051	$ 99,029	$ 535,829	$ 397,969	$ 378,924
Gross profit	25,562	28,564	34,653	26,199	20,329	20,494	23,037	21,365	114,978	85,225	77,807
Net income	$ 5,733	$ 4,158	$ 8,240	$ 3,716	$ 4,133	$ 4,575	$ 5,955	$ 4,492	$ 21,847	$ 19,155	$ 16,806
Earnings per common share:
Basic	$ 0.34	$ 0.25	$ 0.50	$ 0.22	$ 0.25	$ 0.28	$ 0.36	$ 0.27	$ 1.31	$ 1.16	$ 1.01
Diluted	$ 0.34	$ 0.24	$ 0.49	$ 0.22	$ 0.25	$ 0.27	$ 0.35	$ 0.26	$ 1.28	$ 1.14	$ 0.99