Net Income (Loss) per Share - Computation of Basic and Diluted Net Income (Loss) per Share Attributable to Common Stockholders (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net income (loss) applicable to common stockholders	$ 1,209,003	$ 27,102	$ 977,336	$ (136,650)
Denominator:
Weighted average common shares outstanding, basic	15,464,604	15,339,743	15,430,653	15,334,397
Effect of dilutive common shares	3,214	22,663	10,250
Weighted average common shares outstanding, diluted	15,467,818	15,362,406	15,440,903	15,334,397
Net income (loss) per share:
Basic	$ 0.08	$ 0.00	$ 0.06	$ (0.01)
Diluted	$ 0.08	$ 0.00	$ 0.06	$ (0.01)
Anti-dilutive securities excluded from diluted net income (loss) per share:
Anti-dilutive securities excluded from diluted net income (loss) per share	3,863,893	4,423,858	3,867,107	4,446,521
Stock options [Member]
Anti-dilutive securities excluded from diluted net income (loss) per share:
Anti-dilutive securities excluded from diluted net income (loss) per share	3,342,833	2,690,293	3,346,047	2,712,956
Warrants [Member]
Anti-dilutive securities excluded from diluted net income (loss) per share:
Anti-dilutive securities excluded from diluted net income (loss) per share	521,060	1,733,565	521,060	1,733,565