Note 4 - Securities - Available-for-sale Securities by Maturity (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
1-5 years, amortized cost	$ 663,395
1-5 years, fair value	672,379
5-10 years, amortized cost	14,507,941
5-10 years, fair value	14,477,818
After 10 years, amortized cost	23,344,708
After 10 years, fair value	23,465,579
Government sponsored mortgage-backed securities and SBA loan pools not due on a single maturity date, amortized cost	60,510,461
Government sponsored mortgage-backed securities and SBA loan pools not due on a single maturity date, fair value	60,177,882
Available-for-sale securities, amortized cost	99,026,505	$ 88,102,659
Available-for-sale securities	$ 98,793,658	$ 86,266,197

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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