Note 4 - Loans and Allowance for Loan Losses - Loans by Credit Quality (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Loans receivable	$ 753,408,413	$ 728,914,025
Real Estate, Construction [Member]
Loans receivable	70,847,330	77,308,551
Commercial Real Estate Portfolio Segment [Member]
Loans receivable	305,673,212	300,619,387
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	115,799,200	118,823,731
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable	90,028,775	87,448,418
Commercial Portfolio Segment [Member]
Loans receivable	144,326,350	114,047,753
Consumer and Other Loans [Member]
Loans receivable	26,733,546	30,666,185
Pass [Member]
Loans receivable	685,352,000	699,557,000
Pass [Member] | Real Estate, Construction [Member]
Loans receivable	64,531,000	73,489,000
Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	262,771,000	292,674,000
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	110,615,000	115,622,000
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable	90,029,000	87,448,000
Pass [Member] | Commercial Portfolio Segment [Member]
Loans receivable	130,874,000	100,658,000
Pass [Member] | Consumer and Other Loans [Member]
Loans receivable	26,532,000	29,666,000
Special Mention [Member]
Loans receivable	4,565,000	10,804,000
Special Mention [Member] | Real Estate, Construction [Member]
Loans receivable	0	0
Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	4,442,000	1,476,000
Special Mention [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	0	535,000
Special Mention [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable	0	0
Special Mention [Member] | Commercial Portfolio Segment [Member]
Loans receivable	123,000	8,793,000
Special Mention [Member] | Consumer and Other Loans [Member]
Loans receivable	0	0
Substandard [Member]
Loans receivable	63,491,000	18,553,000
Substandard [Member] | Real Estate, Construction [Member]
Loans receivable	6,316,000	3,820,000
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	38,460,000	6,469,000
Substandard [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	5,184,000	2,667,000
Substandard [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable	0	0
Substandard [Member] | Commercial Portfolio Segment [Member]
Loans receivable	13,329,000	4,597,000
Substandard [Member] | Consumer and Other Loans [Member]
Loans receivable	202,000	1,000,000
Doubtful [Member]
Loans receivable	0	0
Doubtful [Member] | Real Estate, Construction [Member]
Loans receivable	0	0
Doubtful [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	0	0
Doubtful [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	0	0
Doubtful [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable	0	0
Doubtful [Member] | Commercial Portfolio Segment [Member]
Loans receivable	0	0
Doubtful [Member] | Consumer and Other Loans [Member]
Loans receivable	$ 0	$ 0