Note 2 - Securities - Available-for-sale Securities by Maturity (Details)	Dec. 31, 2017 USD ($)
1-5 years, amortized cost	$ 563,318
1-5 years, fair value	571,615
5-10 years, amortized cost	9,238,773
5-10 years, fair value	9,278,788
After ten years, amortized cost	27,106,116
After ten years, fair value	27,113,055
Government sponsored mortgage-backed securities and SBA loan pools not due on a single maturity date, amortized cost	45,414,845
Government sponsored mortgage-backed securities and SBA loan pools not due on a single maturity date, fair value	44,515,215
Amortized cost	82,323,052
Fair value	$ 81,478,673