Note 4 - Loans and Allowance for Loan Losses - Loans by Credit Quality (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Loans receivable	$ 728,914,025	$ 786,894,894
Real Estate, Construction [Member]
Loans receivable	77,308,551	88,553,995
Commercial Real Estate Portfolio Segment [Member]
Loans receivable	300,619,387	322,921,323
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	118,823,731	132,410,810
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable	87,448,418	90,548,265
Commercial Portfolio Segment [Member]
Loans receivable	114,047,753	119,369,484
Consumer and Other Loans [Member]
Loans receivable	30,666,185	33,091,017
Pass [Member]
Loans receivable	699,557,000	753,254,000
Pass [Member] | Real Estate, Construction [Member]
Loans receivable	73,489,000	84,375,000
Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	292,674,000	310,486,000
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	115,622,000	126,586,000
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable	87,448,000	84,596,000
Pass [Member] | Commercial Portfolio Segment [Member]
Loans receivable	100,658,000	114,525,000
Pass [Member] | Consumer and Other Loans [Member]
Loans receivable	29,666,000	32,686,000
Special Mention [Member]
Loans receivable	10,804,000	8,927,000
Special Mention [Member] | Real Estate, Construction [Member]
Loans receivable	0	0
Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	1,476,000	5,524,000
Special Mention [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	535,000	372,000
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	8,793,000	3,031,000
Special Mention [Member] | Consumer and Other Loans [Member]
Loans receivable	0	0
Substandard [Member]
Loans receivable	18,553,000	24,714,000
Substandard [Member] | Real Estate, Construction [Member]
Loans receivable	3,820,000	4,179,000
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	6,469,000	6,911,000
Substandard [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	2,667,000	5,453,000
Substandard [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable		5,952,000
Substandard [Member] | Commercial Portfolio Segment [Member]
Loans receivable	4,597,000	1,814,000
Substandard [Member] | Consumer and Other Loans [Member]
Loans receivable	1,000,000	405,000
Doubtful [Member]
Loans receivable
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
Doubtful [Member] | Consumer and Other Loans [Member]
Loans receivable	$ 0	$ 0