Note 6 - Other Real Estate Owned (Details Textual) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Real Estate, Ending Balance	$ 1,635	$ 1,841	$ 4,256
Other Real Estate, Foreclosed Assets, and Repossessed Assets, Total	359	565
Mortgage Loans in Process of Foreclosure, Amount	$ 157	$ 25