Note 3 - Investment Securities - Gross Unrealized Losses on Continuous Basis for Investment Securities (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
Less than 12 months Fair value	$ 119,917,651	$ 124,609,499
Less than 12 months Unrealized losses	8,972,322	2,126,119
12 months or more Fair value	21,098,288	6,630,634
12 months or more Unrealized losses	2,502,801	278,417
Total Fair value	141,015,939	131,240,133
Total Unrealized losses	11,475,123	2,404,536
US States and Political Subdivisions Debt Securities [Member]
Less than 12 months Fair value	7,738,761	1,324,648
Less than 12 months Unrealized losses	412,339	35,720
12 months or more Fair value	924,219	715,650
12 months or more Unrealized losses	178,268	31,531
Total Fair value	8,662,980	2,040,298
Total Unrealized losses	590,607	67,251
SBA Pools [Member]
Less than 12 months Fair value	0	0
Less than 12 months Unrealized losses	0	0
12 months or more Fair value	1,039,389	1,133,398
12 months or more Unrealized losses	22,049	22,664
Total Fair value	1,039,389	1,133,398
Total Unrealized losses	22,049	22,664
Corporate Debt Securities [Member]
Less than 12 months Fair value	8,201,181	5,443,886
Less than 12 months Unrealized losses	347,754	55,541
12 months or more Fair value	0	0
12 months or more Unrealized losses	0	0
Total Fair value	8,201,181	5,443,886
Total Unrealized losses	347,754	55,541
Collateralized Mortgage-Backed Securities [Member]
Less than 12 months Fair value	103,977,709	117,840,965
Less than 12 months Unrealized losses	8,212,229	2,034,858
12 months or more Fair value	19,134,680	4,781,586
12 months or more Unrealized losses	2,302,484	224,222
Total Fair value	123,112,389	122,622,551
Total Unrealized losses	$ 10,514,713	$ 2,259,080