Note 3 - Investment Securities - Investments in Debt Securities (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Amortized cost, available for sale	$ 30,973,514	$ 27,376,040
Unrealized gains, available for sale	110,657	44,755
Unrealized losses, available for sale	482,400	828,804
Fair value, available for sale	30,601,771	26,591,991
Amortized cost, held to maturity	18,065,993	18,127,067
Fair value, held to maturity	18,236,185	18,033,093
US States and Political Subdivisions Debt Securities [Member]
Amortized cost, available for sale	1,130,283	1,506,011
Unrealized gains, available for sale	8,235	11,161
Unrealized losses, available for sale	5,228	10,667
Fair value, available for sale	1,133,290	1,506,505
Amortized cost, held to maturity	18,065,993	18,127,067
Unrealized gains, held to maturity	220,230	115,220
Unrealized losses, held to maturity	50,038	209,194
Fair value, held to maturity	18,236,185	18,033,093
SBA Pools [Member]
Amortized cost, available for sale	2,658,758	2,779,411
Unrealized gains, available for sale
Unrealized losses, available for sale	54,648	60,039
Fair value, available for sale	2,604,110	2,719,372
Collateralized Mortgage Backed Securities [Member]
Amortized cost, available for sale	27,184,473	23,090,618
Unrealized gains, available for sale	102,422	33,594
Unrealized losses, available for sale	422,524	758,098
Fair value, available for sale	$ 26,864,371	$ 22,366,114

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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