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, 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)
Other comprehensive income				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)
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
Balance at Dec. 31, 2021	$ 131,815,739	$ (2,423,007)	8,835,203	9,818,605	(68,783,207)	79,263,333
Balance (in shares) at Dec. 31, 2021	24,202,218	(534,015)
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)
Increase (Decrease) in Stockholders' Equity
Net income					(485,025)	(485,025)
Stock-based compensation expenses			236,041			236,041
Buyback of common shares		$ (568,989)				(568,989)
Buyback of common shares (in shares)		(141,015)
Other comprehensive income				(1,484)		(1,484)
Balance at Jun. 30, 2021	$ 131,730,401	$ (1,061,468)	8,317,659	9,819,405	(78,160,182)	70,645,816
Balance (in shares) at Jun. 30, 2021	23,985,799	(264,215)
Balance at Dec. 31, 2021	$ 131,815,739	$ (2,423,007)	8,835,203	9,818,605	(68,783,207)	79,263,333
Balance (in shares) at Dec. 31, 2021	24,202,218	(534,015)
Increase (Decrease) in Stockholders' Equity
Net income					5,805,888	5,805,888
Dividends					(1,483,027)	(1,483,027)
Stock-based compensation expenses			142,302			142,302
Exercise of stock options	$ 209,312					209,312
Exercise of stock options (in shares)	38,750
Retirement of treasury shares	$ (2,423,007)	$ 2,423,007
Retirement of treasury shares (in shares)	(534,015)	534,015
Other comprehensive income				5,402		5,402
Balance at Mar. 31, 2022	$ 129,602,044		8,977,505	9,824,007	(64,460,346)	83,943,210
Balance (in shares) at Mar. 31, 2022	23,706,953
Balance at Dec. 31, 2021	$ 131,815,739	$ (2,423,007)	8,835,203	9,818,605	(68,783,207)	$ 79,263,333
Balance (in shares) at Dec. 31, 2021	24,202,218	(534,015)
Increase (Decrease) in Stockholders' Equity
Purchase of treasury shares (shares)						(697,100)
Balance at Jun. 30, 2022	$ 127,093,520	$ (1,646,823)	9,171,555	9,804,857	(55,364,008)	$ 89,059,101
Balance (in shares) at Jun. 30, 2022	23,356,453	(274,100)
Balance at Mar. 31, 2022	$ 129,602,044		8,977,505	9,824,007	(64,460,346)	83,943,210
Balance (in shares) at Mar. 31, 2022	23,706,953
Increase (Decrease) in Stockholders' Equity
Net income					10,582,988	10,582,988
Dividends					(1,486,650)	(1,486,650)
Stock-based compensation expenses			194,050			194,050
Exercise of stock options	$ 399,475					399,475
Exercise of stock options (in shares)	72,500
Retirement of treasury shares	$ (2,907,999)	$ 2,907,999
Retirement of treasury shares (in shares)	(423,000)	423,000
Buyback of common shares		$ (4,554,822)				$ (4,554,822)
Buyback of common shares (in shares)		(697,100)				(423,000)
Other comprehensive income				(19,150)		$ (19,150)
Balance at Jun. 30, 2022	$ 127,093,520	$ (1,646,823)	$ 9,171,555	$ 9,804,857	$ (55,364,008)	$ 89,059,101
Balance (in shares) at Jun. 30, 2022	23,356,453	(274,100)