Note 5 - Loans and Allowance for Loan Losses - Loans by Credit Quality (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Rating:
Loans receivable	$ 768,965,653	$ 786,894,894
Real Estate, Construction [Member]
Rating:
Loans receivable	89,605,230	88,553,995
Commercial Real Estate Portfolio Segment [Member]
Rating:
Loans receivable	310,375,931	322,921,323
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Rating:
Loans receivable	127,332,191	132,410,810
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Rating:
Loans receivable	92,045,496	90,548,265
Commercial Portfolio Segment [Member]
Rating:
Loans receivable	118,295,271	119,369,484
Consumer and Other Loans [Member]
Rating:
Loans receivable	31,311,534	33,091,017
Pass [Member]
Rating:
Loans receivable	734,692,000	753,254,000
Pass [Member] | Real Estate, Construction [Member]
Rating:
Loans receivable	85,512,000	84,375,000
Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Rating:
Loans receivable	297,890,000	310,486,000
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Rating:
Loans receivable	122,150,000	126,586,000
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Rating:
Loans receivable	86,116,000	84,596,000
Pass [Member] | Commercial Portfolio Segment [Member]
Rating:
Loans receivable	112,875,000	114,525,000
Pass [Member] | Consumer and Other Loans [Member]
Rating:
Loans receivable	30,149,000	32,686,000
Special Mention [Member]
Rating:
Loans receivable	10,455,000	8,927,000
Special Mention [Member] | Real Estate, Construction [Member]
Rating:
Loans receivable	0	0
Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member]
Rating:
Loans receivable	5,405,000	5,524,000
Special Mention [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Rating:
Loans receivable	363,000	372,000
Special Mention [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Rating:
Loans receivable	0	0
Special Mention [Member] | Commercial Portfolio Segment [Member]
Rating:
Loans receivable	3,889,000	3,031,000
Special Mention [Member] | Consumer and Other Loans [Member]
Rating:
Loans receivable	798,000	0
Substandard [Member]
Rating:
Loans receivable	23,819,000	24,714,000
Substandard [Member] | Real Estate, Construction [Member]
Rating:
Loans receivable	4,093,000	4,179,000
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member]
Rating:
Loans receivable	7,081,000	6,911,000
Substandard [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Rating:
Loans receivable	4,819,000	5,453,000
Substandard [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Rating:
Loans receivable	5,930,000	5,952,000
Substandard [Member] | Commercial Portfolio Segment [Member]
Rating:
Loans receivable	1,531,000	1,814,000
Substandard [Member] | Consumer and Other Loans [Member]
Rating:
Loans receivable	365,000	405,000
Doubtful [Member]
Rating:
Loans receivable
Doubtful [Member] | Real Estate, Construction [Member]
Rating:
Loans receivable	0	0
Doubtful [Member] | Commercial Real Estate Portfolio Segment [Member]
Rating:
Loans receivable	0	0
Doubtful [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Rating:
Loans receivable	0	0
Doubtful [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Rating:
Loans receivable	0	0
Doubtful [Member] | Commercial Portfolio Segment [Member]
Rating:
Loans receivable
Doubtful [Member] | Consumer and Other Loans [Member]
Rating:
Loans receivable	$ 0	$ 0