Note 3 - Securities - Available-for-sale Debt Securities (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Available-for-sale securities, amortized cost	$ 88,102,659	$ 82,323,052
Available-for-sale securities, gross unrealized gains	111,507	328,155
Available-for-sale securities, gross unrealized (losses)	(1,947,969)	(1,172,534)
Available-for-sale securities	86,266,197	81,478,673
US States and Political Subdivisions Debt Securities [Member]
Available-for-sale securities, amortized cost	34,470,648	33,908,207
Available-for-sale securities, gross unrealized gains	10,581	253,872
Available-for-sale securities, gross unrealized (losses)	(710,709)	(263,621)
Available-for-sale securities	33,770,520	33,898,458
Corporate Debt Securities [Member]
Available-for-sale securities, amortized cost	3,000,000	3,000,000
Available-for-sale securities, gross unrealized gains	18,927	65,000
Available-for-sale securities, gross unrealized (losses)
Available-for-sale securities	3,018,927	3,065,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Available-for-sale securities, amortized cost	50,632,011	45,414,845
Available-for-sale securities, gross unrealized gains	81,999	9,283
Available-for-sale securities, gross unrealized (losses)	(1,237,260)	(908,913)
Available-for-sale securities	$ 49,476,750	$ 44,515,215

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on 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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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on 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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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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-Publisher FASB
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Amount 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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