Note 3 - Loans Held for Investment, Net - Credit Quality Indicators (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Total gross loans	$ 270,261,368	$ 244,858,099
Pass [Member]
Total gross loans	259,729,219	231,996,988
Special Mention [Member]
Total gross loans	914,163	855,991
Substandard [Member]
Total gross loans	8,757,790	11,709,120
Doubtful [Member]
Total gross loans	860,196	296,000
Loss [Member]
Total gross loans	0	0
Commercial Real Estate Portfolio Segment [Member]
Total gross loans	220,427,379	195,814,205
Commercial Real Estate Portfolio Segment [Member] | Pass [Member]
Total gross loans	213,778,471	187,069,284
Commercial Real Estate Portfolio Segment [Member] | Special Mention [Member]
Total gross loans	914,163	523,207
Commercial Real Estate Portfolio Segment [Member] | Substandard [Member]
Total gross loans	5,184,745	8,221,714
Commercial Real Estate Portfolio Segment [Member] | Doubtful [Member]
Total gross loans	550,000	0
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	30,135,267	29,976,625
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Pass [Member]
Total gross loans	28,476,696	28,232,563
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Special Mention [Member]
Total gross loans	0	65,457
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Substandard [Member]
Total gross loans	1,642,573	1,678,605
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Doubtful [Member]
Total gross loans	15,998	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	14,593,471	9,876,020
Commercial and Industrial Portfolio Segment [Member] | Pass [Member]
Total gross loans	12,546,259	7,697,960
Commercial and Industrial Portfolio Segment [Member] | Special Mention [Member]
Total gross loans		267,327
Commercial and Industrial Portfolio Segment [Member] | Substandard [Member]
Total gross loans	1,753,014	1,614,733
Commercial and Industrial Portfolio Segment [Member] | Doubtful [Member]
Total gross loans	294,198	296,000
Commercial and Industrial Portfolio Segment [Member] | Loss [Member]
Total gross loans	0	0
Consumer and Other Portfolio Segment [Member]
Total gross loans	5,105,251	9,191,249
Consumer and Other Portfolio Segment [Member] | Pass [Member]
Total gross loans	4,927,793	8,997,181
Consumer and Other Portfolio Segment [Member] | Special Mention [Member]
Total gross loans	0	0
Consumer and Other Portfolio Segment [Member] | Substandard [Member]
Total gross loans	177,458	194,068
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