Note 7 - Investments, Held to Maturity ("HTM") - Summary of Held to Maturity Securities (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Amortized cost, HTM	$ 174,136,215	$ 167,437,616
Gross unrealized gains, HTM	856,331	279,918
Gross unrealized losses, HTM	(8,353,850)	(6,253,961)
HTM, fair value	166,638,696	161,463,573
US Treasury and Government [Member]
Amortized cost, HTM	34,782,248	34,511,849
Gross unrealized gains, HTM	0	0
Gross unrealized losses, HTM	(587,405)	(682,198)
HTM, fair value	34,194,843	33,829,651
Federal Home Loan Bank Certificates and Obligations (FHLB) [Member]
Amortized cost, HTM	1,000,000	1,000,000
Gross unrealized gains, HTM	0	0
Gross unrealized losses, HTM	(13,279)	(1,360)
HTM, fair value	986,721	998,640
Collateralized Loan Obligations [Member]
Amortized cost, HTM	17,510,213	16,387,997
Gross unrealized gains, HTM	272,590	88,489
Gross unrealized losses, HTM	0	(59,090)
HTM, fair value	17,782,803	16,417,396
Small Business Administration Bonds [Member]
Amortized cost, HTM	12,689,280	3,521,293
Gross unrealized gains, HTM	583,741	162,235
Gross unrealized losses, HTM	0	0
HTM, fair value	13,273,021	3,683,528
Taxable Municipal Bonds [Member]
Amortized cost, HTM	959,701	951,864
Gross unrealized gains, HTM	0	0
Gross unrealized losses, HTM	(53,531)	(60,134)
HTM, fair value	906,170	891,730
Collateralized Mortgage-Backed Securities [Member]
Amortized cost, HTM	107,194,773	111,064,613
Gross unrealized gains, HTM	0	29,194
Gross unrealized losses, HTM	(7,699,635)	(5,451,179)
HTM, fair value	$ 99,495,138	$ 105,642,628