Note 8 - Deposits - Public Entity Deposits (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Collateralized by investment securities	$ 10,863,081	$ 10,019,425
U.S. govt. sponsored agency securities
Collateralized by investment securities	980,160	983,670
Residential Mortgage Backed Securities
Collateralized by investment securities	$ 9,882,921	$ 9,035,755