Note 4 - Loans Held for Investment, Net - Nonperforming Receivables Past Due (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Past due loans	$ 1,262,147	$ 4,152,071
Current loans	312,417,394	291,316,517
Total	313,679,541	295,468,588
Financial Asset, 30 to 59 Days Past Due [Member]
Past due loans	1,052,985	758,197
Financial Asset, 60 to 89 Days Past Due [Member]
Past due loans		36,520
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due loans	209,162	3,357,354
Commercial Real Estate Portfolio Segment [Member]
Past due loans		2,718,731
Current loans	248,763,039	239,963,990
Total	248,763,039	242,682,721
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due loans
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due loans
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due loans		2,718,731
One-to-four Family Residential Real Estate Portfolio Segment [Member]
Past due loans	1,262,147	1,433,340
Current loans	26,431,443	27,416,300
Total	27,693,590	28,849,640
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due loans	1,052,985	758,197
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due loans		36,520
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due loans	209,162	638,623
Commercial and Industrial Portfolio Segment [Member]
Past due loans
Current loans	34,081,604	20,075,236
Total	34,081,604	20,075,236
Commercial and Industrial Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due loans	0	0
Commercial and Industrial Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due loans	0	0
Commercial and Industrial Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due loans
Consumer and Other Portfolio Segment [Member]
Past due loans	0	0
Current loans	3,141,308	3,860,991
Total	3,141,308	3,860,991
Consumer and Other Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due loans	0	0
Consumer and Other Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due loans	0	0
Consumer and Other Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due loans	$ 0	$ 0