Selected Quarterly Financial Data (unaudited) (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 82,077	$ 71,882	$ 58,756	$ 55,530	$ 56,041	$ 50,376	$ 46,713	$ 44,762	$ 238,573	$ 185,230	$ 160,313
Gross margin	49,770	46,565	37,299	36,902	36,988	31,068	30,723	29,868	170,536	128,647	101,548
Net income	$ 6,341	$ 3,843	$ 3,650	$ 3,463	$ 5,104	$ 1,521	$ 6,103	$ 7,205	$ 17,297	$ 19,933	$ 19,918
Earnings per share
Basic (in dollars per share)	$ 0.12	$ 0.07	$ 0.07	$ 0.06	$ 0.10	$ 0.03	$ 0.11	$ 0.14	$ 0.33	$ 0.37	$ 0.38
Diluted (in dollars per share)	$ 0.12	$ 0.07	$ 0.07	$ 0.06	$ 0.09	$ 0.03	$ 0.11	$ 0.13	$ 0.32	$ 0.36	$ 0.37