Net Income (Loss) Per Share - Summary of Computation of Net Income (Loss) Per Share (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Numerator:
Net income (loss)	$ 336,443	$ (1,105,791)
Denominator:
Basic	9,625,678	9,479,742
Plus dilutive effect of potential common shares	335,370
Weighted average common shares outstanding - diluted	9,961,048	9,479,742
Net income (loss) per share:
Basic	$ 0.03	$ (0.12)
Diluted	$ 0.03	$ (0.12)