Note 2 - Investments - Amortized Cost and Fair Value of Debt Securities By Contractual Maturity (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
After one year through five years, amortized cost	$ 1,573,995	$ 1,472,228
After one year through five years, fair value	1,591,192	1,462,745
After five years through ten years, amortized cost	2,142,756	2,101,676
After five years through ten years, fair value	2,181,773	2,055,173
More than 10 years, amortized cost	20,891,772	20,430,838
More than 10 years, fair value	21,000,026	19,492,496
Total amortized cost and fair value	28,510,195	27,957,697
Total amortized cost and fair value	28,671,748	26,882,239
Redeemable Preferred Stock [Member]
Debt securities, amortized cost	99,560	99,560
Debt securities, fair value	99,200	90,840
Collateralized Mortgage Backed Securities [Member]
Debt securities, amortized cost	3,802,112	3,853,395
Debt securities, fair value	$ 3,799,557	$ 3,780,985

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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