Net Income (Loss) Per Share - Summary of Computation of Net Income (Loss) Per Share (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Numerator:
Net income (loss)	$ (3,190,347)	$ (70,121)	$ (4,296,138)	$ 314,970
Denominator:
Basic	9,439,025	9,520,285	9,459,272	9,440,368
Plus dilutive effect of potential common shares				680,630
Weighted average common shares outstanding - diluted	9,439,025	9,520,285	9,459,272	10,120,998
Net income (loss) per share:
Basic	$ (0.34)	$ (0.01)	$ (0.45)	$ 0.03
Diluted	$ (0.34)	$ (0.01)	$ (0.45)	$ 0.03