Note 11 - Financial Instruments with Off-balance Sheet Risk - Financial Instruments With Credit Risk (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Commitments to extend credit	$ 142,148	$ 145,065
Unused Line of Credit [Member]
Commitments to extend credit	63,560	71,101
Undisbursed Construction Loans [Member]
Commitments to extend credit	44,653	25,367
Home Equity Lines of Credit [Member]
Commitments to extend credit	19,146	20,032
Future Loan Commitments [Member]
Commitments to extend credit	14,046	27,822
Financial Standy Letter of Credit [Member]
Commitments to extend credit	$ 743	$ 743