Note 5 - Loans Held for Investment, Net - Credit Quality Indicators (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Total, gross loans	$ 295,468,588	$ 286,840,889
Pass [Member]
Total, gross loans	288,151,676	278,113,442
Special Mention [Member]
Total, gross loans	883,255	2,250,559
Substandard [Member]
Total, gross loans	6,433,657	6,476,888
Doubtful [Member]
Total, gross loans
Loss [Member]
Total, gross loans	0	0
Commercial Real Estate Portfolio Segment [Member]
Total, gross loans	242,682,721	233,102,637
Commercial Real Estate Portfolio Segment [Member] | Pass [Member]
Total, gross loans	237,546,684	226,510,803
Commercial Real Estate Portfolio Segment [Member] | Special Mention [Member]
Total, gross loans	508,201	1,981,667
Commercial Real Estate Portfolio Segment [Member] | Substandard [Member]
Total, gross loans	4,627,836	4,610,167
Commercial Real Estate Portfolio Segment [Member] | Doubtful [Member]
Total, gross loans
Commercial Real Estate Portfolio Segment [Member] | Loss [Member]
Total, gross loans	0	0
One-to-four Family Residential Real Estate Portfolio Segment [Member]
Total, gross loans	28,849,640	29,855,462
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Pass [Member]
Total, gross loans	26,969,204	27,990,417
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Special Mention [Member]
Total, gross loans	375,054	268,892
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Substandard [Member]
Total, gross loans	1,505,382	1,596,153
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Doubtful [Member]
Total, gross loans	0	0
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Loss [Member]
Total, gross loans	0	0
Commercial and Industrial Portfolio Segment [Member]
Total, gross loans	20,075,236	17,508,258
Commercial and Industrial Portfolio Segment [Member] | Pass [Member]
Total, gross loans	19,774,797	17,237,690
Commercial and Industrial Portfolio Segment [Member] | Special Mention [Member]
Total, gross loans
Commercial and Industrial Portfolio Segment [Member] | Substandard [Member]
Total, gross loans	300,439	270,568
Commercial and Industrial Portfolio Segment [Member] | Doubtful [Member]
Total, gross loans	0	0
Commercial and Industrial Portfolio Segment [Member] | Loss [Member]
Total, gross loans	0	0
Consumer and Other Portfolio Segment [Member]
Total, gross loans	3,860,991	6,374,532
Consumer and Other Portfolio Segment [Member] | Pass [Member]
Total, gross loans	3,860,991	6,374,532
Consumer and Other Portfolio Segment [Member] | Special Mention [Member]
Total, gross loans	0
Consumer and Other Portfolio Segment [Member] | Substandard [Member]
Total, gross loans
Consumer and Other Portfolio Segment [Member] | Doubtful [Member]
Total, gross loans	0	0
Consumer and Other Portfolio Segment [Member] | Loss [Member]
Total, gross loans	$ 0	$ 0