Selected Quarterly Financial Data (unaudited) (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 171,851	$ 130,837	$ 112,362	$ 115,810	$ 114,791	$ 104,836	$ 99,226	$ 101,215		$ 530,860	$ 420,068	$ 343,798
Gross margin	92,640	80,169	65,560	68,917	65,346	65,633	63,143	64,461		307,286	258,583	207,088
Net income	$ (12,379)	$ 6,104	$ 738	$ 6,419	$ 2,083	$ 5,711	$ 8,485	$ 12,926	$ 5,207	$ 882	$ 29,205	$ 5,207
Earnings (loss) per share
Basic (in dollars per share)	$ (0.21)	$ 0.10	$ 0.01	$ 0.11	$ 0.04	$ 0.10	$ 0.15	$ 0.24		$ 0.01	$ 0.52	$ 0.10
Diluted (in dollars per share)	$ (0.21)	$ 0.10	$ 0.01	$ 0.11	$ 0.03	$ 0.10	$ 0.15	$ 0.24		$ 0.01	$ 0.50	$ 0.10
Total out of period adjustments					$ 1,800
Decrease to net sales					900
Increase sales, general and administration expense					1,300
Decrease to provision income taxes					$ 400