Note 7 - Investment Securities - Amortized Cost and Fair Values of Securities (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Securities available for sale, amortized cost	$ 24,345,855	$ 25,577,244
Securities available for sale, gross unrealized gains	258,540	175,409
Securities available for sale, gross unrealized losses	134,396	218,886
Securities available for sale	24,469,999	25,533,767
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale, amortized cost	12,569,484	13,092,077
Securities available for sale, gross unrealized gains	184,283	116,127
Securities available for sale, gross unrealized losses	2,780	21,416
Securities available for sale	12,750,987	13,186,788
Residential Mortgage Backed Securities [Member]
Securities available for sale, amortized cost	11,776,371	12,485,167
Securities available for sale, gross unrealized gains	74,257	59,282
Securities available for sale, gross unrealized losses	131,616	197,470
Securities available for sale	$ 11,719,012	$ 12,346,979

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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-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
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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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