Note 18 - Off Balance Sheet Risks, Commitments, and Contingent Liabilities - Contractual Amounts of Financial Instruments With Off Balance Sheet Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fixed Rate [Member] | Commitments to Make Loans [Member]
Financial Instrument off Balance Sheet Risk, Amount	$ 11,577	$ 5,317
Fixed Rate [Member] | Unused lines of Credit [Member]
Financial Instrument off Balance Sheet Risk, Amount	7,916	7,410
Fixed Rate [Member] | Standby Letters of Credit [Member]
Financial Instrument off Balance Sheet Risk, Amount	531	541
Variable Rate [Member] | Commitments to Make Loans [Member]
Financial Instrument off Balance Sheet Risk, Amount	20,415	11,236
Variable Rate [Member] | Unused lines of Credit [Member]
Financial Instrument off Balance Sheet Risk, Amount	111,230	73,024
Variable Rate [Member] | Standby Letters of Credit [Member]
Financial Instrument off Balance Sheet Risk, Amount	$ 3,164	$ 1,752