Unaudited Condensed Consolidated Statements of Changes in Shareholders' Equity - USD ($)	Common stock	Treasury Shares	Additional paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Total
Balance at Dec. 31, 2019	$ 140,808,923		$ 7,029,488	$ 9,810,478	$ (81,285,895)	$ 76,362,994
Balance (in shares) at Dec. 31, 2019	26,790,985
Increase (Decrease) in Stockholders' Equity
Net income					310,299	310,299
Stock-based compensation expenses			173,919			173,919
Buyback of common shares		$ (1,499,586)				(1,499,586)
Buyback of common shares (in shares)		(488,029)
Other comprehensive income (loss)				(114)		(114)
Balance at Mar. 31, 2020	$ 140,808,923	$ (1,499,586)	7,203,407	9,810,364	(80,975,596)	75,347,512
Balance (in shares) at Mar. 31, 2020	26,790,985	(488,029)
Balance at Dec. 31, 2020	$ 131,730,401		7,879,119	9,820,647	(80,410,724)	69,019,443
Balance (in shares) at Dec. 31, 2020	23,985,799
Increase (Decrease) in Stockholders' Equity
Net income					2,735,567	2,735,567
Stock-based compensation expenses			202,499			202,499
Buyback of common shares		$ (492,479)				$ (492,479)
Buyback of common shares (in shares)		(123,200)				(123,200)
Other comprehensive income (loss)				242		$ 242
Balance at Mar. 31, 2021	$ 131,730,401	$ (492,479)	$ 8,081,618	$ 9,820,889	$ (77,675,157)	$ 71,465,272
Balance (in shares) at Mar. 31, 2021	23,985,799	(123,200)