Note 5 - Loans and Allowance for Loan Losses - Loans by Credit Quality (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Loans receivable	$ 783,474,229	$ 728,914,025
Real Estate, Construction [Member]
Loans receivable	66,354,401	77,308,551
Commercial Real Estate Portfolio Segment [Member]
Loans receivable	306,700,011	300,619,387
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	127,187,806	118,823,731
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable	85,824,232	87,448,418
Commercial Portfolio Segment [Member]
Loans receivable	168,378,978	114,047,753
Consumer and Other Loans [Member]
Loans receivable	29,028,801	30,666,185
Pass [Member]
Loans receivable	749,823,000	699,557,000
Pass [Member] | Real Estate, Construction [Member]
Loans receivable	61,834,000	73,489,000
Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	295,826,000	292,674,000
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	122,677,000	115,622,000
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable	85,824,000	87,448,000
Pass [Member] | Commercial Portfolio Segment [Member]
Loans receivable	154,901,000	100,658,000
Pass [Member] | Consumer and Other Loans [Member]
Loans receivable	28,761,000	29,666,000
Special Mention [Member]
Loans receivable	10,201,000	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	625,000	1,476,000
Special Mention [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	1,035,000	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	8,541,000	8,793,000
Special Mention [Member] | Consumer and Other Loans [Member]
Loans receivable	0	0
Substandard [Member]
Loans receivable	23,450,000	18,553,000
Substandard [Member] | Real Estate, Construction [Member]
Loans receivable	4,520,000	3,820,000
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	10,249,000	6,469,000
Substandard [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable	3,476,000	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	4,937,000	4,597,000
Substandard [Member] | Consumer and Other Loans [Member]
Loans receivable	268,000	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