Quarterly Financial Data (Unaudited) - Summarized Quarterly Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ 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, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 12,278	$ 11,782	$ 10,854	$ 8,432	$ 7,352	$ 6,525	$ 6,945	$ 5,463	$ 43,346	$ 26,285
Gross profit	11,252	10,771	9,880	7,516	6,423	5,546	5,829	4,154	39,419	21,952
Operating income (loss)	3,631	3,480	2,932	62	678	55	74	(2,021)	10,105	(1,214)
Net income (loss)	$ 3,671	$ 3,567	$ 3,436	$ 48	$ 2,801	$ (983)	$ (2,177)	$ (2,381)	$ 10,722	$ (2,740)
Net earnings (loss) per share - basic	$ 0.10	$ 0.10	$ 0.11		$ 0.10	$ (0.04)	$ (0.10)	$ (0.16)	$ 0.31	$ (0.14)
Weighted average shares outstanding - basic	38,501	36,094	32,068	31,297	26,925	25,020	21,888	15,299	34,513	22,322
Net earnings (loss) per share - diluted	$ 0.09	$ 0.09	$ 0.10		$ 0.10	$ (0.04)	$ (0.10)	$ (0.16)	$ 0.29	$ (0.14)
Weighted average shares outstanding - diluted	41,767	39,472	35,308	31,323	27,395	25,020	21,888	15,299	36,991	22,322