Note 5 - Loans and Allowance for Loan Losses - Loans by Credit Quality (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Loans receivable	$ 752,225,370	$ 786,894,894
Real Estate, Construction [Member]
Loans receivable	88,175,253	88,553,995
Commercial Real Estate Portfolio Segment [Member]
Loans receivable	308,270,953	322,921,323
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	121,690,131	132,410,810
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable	93,628,789	90,548,265
Commercial Portfolio Segment [Member]
Loans receivable	108,738,413	119,369,484
Consumer and Other Loans [Member]
Loans receivable	31,721,831	33,091,017
Pass [Member]
Loans receivable	722,456,000	753,254,000
Pass [Member] | Real Estate, Construction [Member]
Loans receivable	84,275,000	84,375,000
Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	297,358,000	310,486,000
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	118,700,000	126,586,000
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable	87,699,000	84,596,000
Pass [Member] | Commercial Portfolio Segment [Member]
Loans receivable	103,864,000	114,525,000
Pass [Member] | Consumer and Other Loans [Member]
Loans receivable	30,560,000	32,686,000
Special Mention [Member]
Loans receivable	9,679,000	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	6,699,000	5,524,000
Special Mention [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	553,000	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	2,427,000	3,031,000
Special Mention [Member] | Consumer and Other Loans [Member]
Loans receivable		0
Substandard [Member]
Loans receivable	20,090,000	24,714,000
Substandard [Member] | Real Estate, Construction [Member]
Loans receivable	3,900,000	4,179,000
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	4,214,000	6,911,000
Substandard [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	2,437,000	5,453,000
Substandard [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable	5,930,000	5,952,000
Substandard [Member] | Commercial Portfolio Segment [Member]
Loans receivable	2,447,000	1,814,000
Substandard [Member] | Consumer and Other Loans [Member]
Loans receivable	1,162,000	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