Calculations for Basic and Diluted Net Income (Loss) Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net income (loss)	$ 2,540	$ 389	$ 3,541	$ (4,407)
Accretion of Series B convertible preferred stock dividends	(289)	(275)	(859)	(818)
Net income (loss) available to common stockholders	$ 2,251	$ 114	$ 2,682	$ (5,225)
Denominator:
Weighted average common shares outstanding - basic	22,448	18,144	20,948	17,868
Net income (loss) per common share - basic	$ 0.10	$ 0.01	$ 0.13	$ (0.29)
Dilutive securities:
Stock options, RSUs, and warrants	925	506	913
Convertible preferred shares	5,957
Weighted average common shares outstanding - diluted	29,330	18,650	21,861	17,868
Net income (loss) per common share - diluted	$ 0.09	$ 0.01	$ 0.12	$ (0.29)
Diluted net income (loss) per common share:
Net income (loss) available to common stockholders	$ 2,251	$ 114	$ 2,682	$ (5,225)
Plus: accretion of Series B convertible preferred stock dividends, if dilutive	289
Net income (loss) available to common stockholders	$ 2,540	$ 114	$ 2,682	$ (5,225)