Note 3 - Loans Held for Investment, Net - Credit Quality Indicators (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Total, gross loans	$ 262,501,925	$ 262,022,508
Pass [Member]
Total, gross loans	251,436,751	251,988,999
Special Mention [Member]
Total, gross loans	1,877,899	954,953
Substandard [Member]
Total, gross loans	8,637,275	8,528,556
Doubtful [Member]
Total, gross loans	550,000	550,000
Loss [Member]
Total, gross loans	0	0
Commercial Real Estate Portfolio Segment [Member]
Total, gross loans	212,600,568	214,871,788
Commercial Real Estate Portfolio Segment [Member] | Pass [Member]
Total, gross loans	204,977,160	208,395,458
Commercial Real Estate Portfolio Segment [Member] | Special Mention [Member]
Total, gross loans	1,877,899	911,571
Commercial Real Estate Portfolio Segment [Member] | Substandard [Member]
Total, gross loans	5,195,509	5,014,759
Commercial Real Estate Portfolio Segment [Member] | Doubtful [Member]
Total, gross loans	550,000	550,000
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	29,940,894	29,114,060
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Pass [Member]
Total, gross loans	28,255,185	27,400,698
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Special Mention [Member]
Total, gross loans	0	43,382
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Substandard [Member]
Total, gross loans	1,685,709	1,669,980
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	13,543,545	12,296,308
Commercial and Industrial Portfolio Segment [Member] | Pass [Member]
Total, gross loans	11,953,340	10,624,210
Commercial and Industrial Portfolio Segment [Member] | Special Mention [Member]
Total, gross loans	0
Commercial and Industrial Portfolio Segment [Member] | Substandard [Member]
Total, gross loans	1,590,205	1,672,098
Commercial and Industrial Portfolio Segment [Member] | Doubtful [Member]
Total, gross loans	0
Commercial and Industrial Portfolio Segment [Member] | Loss [Member]
Total, gross loans	0	0
Consumer and Other Portfolio Segment [Member]
Total, gross loans	6,416,918	5,740,352
Consumer and Other Portfolio Segment [Member] | Pass [Member]
Total, gross loans	6,251,066	5,568,633
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	165,852	171,719
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