Selected Quarterly Results (Unaudited) (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	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, 2020	Dec. 31, 2019	Dec. 31, 2018
Selected Quarterly Financial Information [Abstract]
Revenue	$ 42,168	$ 39,443	$ 36,582	$ 38,278	$ 31,637	$ 30,306	$ 29,677	$ 19,769	$ 18,028	$ 14,156	$ 12,175	$ 11,281	$ 156,471	$ 111,389	$ 55,640
Gross profit	33,874	34,067	31,147	32,718	24,372	24,956	24,754	15,717	14,005	10,377	7,609	7,866
Income (loss) from operations	12,455	11,606	2,936	5,982	613	1,596	2,799	(1,272)	(4,448)	(3,811)	(7,266)	(8,123)	32,979	3,736	(23,648)
Net income	$ 10,197	$ 9,383	$ 1,165	$ 4,966	$ (696)	$ 354	$ (11,130)	$ (3,833)	$ (7,008)	$ (18,880)	$ (9,770)	$ (10,709)	$ 25,711	$ (15,305)	$ (46,367)
Basic (loss) earnings per share (in usd per share)	$ 0.10	$ 0.09	$ 0.01	$ 0.05	$ 0	$ 0	$ (0.13)	$ (0.05)	$ (0.13)	$ (0.29)	$ (0.16)	$ (0.18)	$ 0.26	$ (0.18)	$ (0.73)
Diluted (loss) earnings per share (in usd per share)	$ 0.10	$ 0.09	$ 0.01	$ 0.05	$ 0	$ 0	$ (0.13)	$ (0.05)	$ (0.13)	$ (0.29)	$ (0.16)	$ (0.18)	$ 0.24	$ (0.18)	$ (0.73)