SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Earnings per share (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Earnings per share
Common Stock underlying issued and outstanding stock options	26,604	96,244
Common stock issuable upon the conversion of convertible preferred shares		232,445
Diluted EPS calculated under the treasury stock method	26,604	328,689
Net Income	$ 990,972	$ 7,616,455
Preferred stock dividend requirements	(58,111)	(58,111)
Net income (loss) applicable to common shareholders	$ 932,861	$ 7,558,344
Average common shares outstanding	29,937,159	33,265,453
Average common and common equivalent shares outstanding - assuming dilution	29,963,763	33,594,142
Basic earnings per share	$ 0.03	$ 0.23
Diluted earnings per share	$ 0.03	$ 0.23