SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Earnings per share (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings per share
Common Stock underlying issued and outstanding stock options	60,462	142,552	76,370	143,780
Common stock issuable upon the conversion of convertible preferred shares	232,445	236,445	232,445	236,445
Diluted EPS calculated under the treasury stock method	292,907	378,997	308,815	380,225
Net Income	$ 5,385,254	$ 6,521,885	$ 9,360,113	$ 35,139,894
Preferred stock dividend requirements	(58,111)	(59,111)	(174,333)	(183,219)
Net income applicable to common shareholders	$ 5,327,143	$ 6,462,774	$ 9,185,780	$ 34,956,675
Average common shares outstanding	32,936,959	33,883,684	33,049,411	33,950,742
Average common and common equivalent shares outstanding - assuming dilution	33,229,866	34,262,681	33,358,225	34,330,967
Basic earnings per share	$ 0.16	$ 0.19	$ 0.28	$ 1.03
Diluted earnings per share	$ 0.16	$ 0.19	$ 0.28	$ 1.02