Note 5 - Loans - Past Due Loans (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Loans, past due	$ 284,686	$ 1,024,318
Loans, current	362,210,017	342,916,524
Loans	362,494,703	343,940,842
Loans, 90 days past due and still accruing		10,507
Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due	284,686
Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due		25,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due		999,318
Commercial Real Estate Portfolio Segment [Member]
Loans, past due	224,794	988,811
Loans, current	240,713,355	237,845,338
Loans	240,938,149	238,834,149
Loans, 90 days past due and still accruing
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due	224,794
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due		988,811
Construction and Land Development [Member]
Loans, past due
Loans, current	18,194,955	18,265,505
Loans	18,194,955	18,265,505
Loans, 90 days past due and still accruing
Construction and Land Development [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due
Construction and Land Development [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due
Construction and Land Development [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due
Residential Portfolio Segment [Member]
Loans, past due	59,892	10,507
Loans, current	76,062,177	63,013,599
Loans	76,122,069	63,024,106
Loans, 90 days past due and still accruing		10,507
Residential Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due	59,892
Residential Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due
Residential Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due		10,507
Commercial Portfolio Segment [Member]
Loans, past due		25,000
Loans, current	26,947,503	23,298,073
Loans	26,947,503	23,323,073
Loans, 90 days past due and still accruing
Commercial Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due
Commercial Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due		25,000
Commercial Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due
Consumer Portfolio Segment [Member]
Loans, past due
Loans, current	292,027	494,009
Loans	292,027	494,009
Loans, 90 days past due and still accruing
Consumer Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due
Consumer Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due
Consumer Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due