Note 4 - Loans - Past Due Loans (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Loans, past due	$ 1,262,921	$ 1,024,318
Loans, current	336,927,860	342,916,524
Loans	338,190,781	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	274,110
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	988,811	999,318
Commercial Real Estate Portfolio Segment [Member]
Loans, past due	988,811	988,811
Loans, current	235,805,491	237,845,338
Loans	236,794,302	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
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	988,811
Construction and Land Development [Member]
Loans, past due
Loans, current	15,914,131	18,265,505
Loans	15,914,131	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	274,110	10,507
Loans, current	62,745,639	63,013,599
Loans	63,019,749	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	274,110
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	22,095,306	23,298,073
Loans	22,095,306	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	367,293	494,009
Loans	367,293	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