Note 8 - Deposits - Public Entity Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Collateralized by investment securities	$ 9,917	$ 10,863
U.S. govt. sponsored agency securities
Collateralized by investment securities	6,135	980
Residential mortgage-backed and related securities
Collateralized by investment securities	$ 3,782	$ 9,883