Note 7 - Investments, Held to Maturity ("HTM") - Summary of HTM Securities in Unrealized Loss Position (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Fair value, less than 12 months, HTM	$ 53,302,533	$ 130,591,167
Unrealized losses, les then 12 months, HTM	(1,257,041)	(3,947,948)
Fair value, more than 12 months, HTM	82,280,339	9,334,438
Unrealized loss, more than 12 months, HTM	(7,096,809)	(2,306,013)
Fair value, unrealized loss position, HTM	135,582,872	139,925,605
Unrealized loss, unrealized loss position, HTM	(8,353,850)	(6,253,961)
US Treasury and Government [Member]
Fair value, less than 12 months, HTM	0	33,829,651
Unrealized losses, les then 12 months, HTM	0	(682,198)
Fair value, more than 12 months, HTM	34,194,843	0
Unrealized loss, more than 12 months, HTM	(587,405)	0
Fair value, unrealized loss position, HTM	34,194,843	33,829,651
Unrealized loss, unrealized loss position, HTM	(587,405)	(682,198)
Federal Home Loan Bank Certificates and Obligations (FHLB) [Member]
Fair value, less than 12 months, HTM	986,721	998,640
Unrealized losses, les then 12 months, HTM	(13,279)	(1,360)
Fair value, more than 12 months, HTM	0	0
Unrealized loss, more than 12 months, HTM	0	0
Fair value, unrealized loss position, HTM	986,721	998,640
Unrealized loss, unrealized loss position, HTM	(13,279)	(1,360)
Taxable Municipal Bonds [Member]
Fair value, less than 12 months, HTM	0	891,730
Unrealized losses, les then 12 months, HTM	0	(60,134)
Fair value, more than 12 months, HTM	906,170	0
Unrealized loss, more than 12 months, HTM	(53,531)	0
Fair value, unrealized loss position, HTM	906,170	891,730
Unrealized loss, unrealized loss position, HTM	(53,531)	(60,134)
Collateralized Loan Obligations [Member]
Fair value, less than 12 months, HTM		6,520,050
Unrealized losses, les then 12 months, HTM		(59,090)
Fair value, more than 12 months, HTM		0
Unrealized loss, more than 12 months, HTM		0
Fair value, unrealized loss position, HTM		6,520,050
Unrealized loss, unrealized loss position, HTM		(59,090)
Collateralized Mortgage-Backed Securities [Member]
Fair value, less than 12 months, HTM	52,315,812	88,351,096
Unrealized losses, les then 12 months, HTM	(1,243,762)	(3,145,166)
Fair value, more than 12 months, HTM	47,179,326	9,334,438
Unrealized loss, more than 12 months, HTM	(6,455,873)	(2,306,013)
Fair value, unrealized loss position, HTM	99,495,138	97,685,534
Unrealized loss, unrealized loss position, HTM	$ (7,699,635)	$ (5,451,179)