Note 5 - Loans Held for Investment, Net - Nonperforming Receivables Past Due (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Past due loans	$ 4,152,071	$ 4,154,832
Current loans	291,316,517	282,686,057
Total, gross loans	295,468,588	286,840,889
Financial Asset, 30 to 59 Days Past Due [Member]
Past due loans	758,197	782,835
Financial Asset, 60 to 89 Days Past Due [Member]
Past due loans	36,520	2,978,929
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due loans	3,357,354	393,068
Commercial Real Estate Portfolio Segment [Member]
Past due loans	2,718,731	2,744,405
Current loans	239,963,990	230,358,232
Total, gross loans	242,682,721	233,102,637
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		2,744,405
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	1,433,340	1,410,427
Current loans	27,416,300	28,445,035
Total, gross loans	28,849,640	29,855,462
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due loans	758,197	782,835
One-to-four Family Residential Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due loans	36,520	234,524
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	638,623	393,068
Commercial and Industrial Portfolio Segment [Member]
Past due loans
Current loans	20,075,236	17,508,258
Total, gross loans	20,075,236	17,508,258
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	3,860,991	6,374,532
Total, gross loans	3,860,991	6,374,532
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