Note 4 - Loans and the Allowance for Credit Losses - Rollforward of Allowance for Credit Losses for Unfunded Commitments (Details) - Unfunded Loan Commitment [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Balance as of beginning of period	$ 2,351	$ 0
Provision for (reversal of) credit losses - unfunded commitments	684	(482)
Balance as of end of period	3,035	2,351
Cumulative Effect, Period of Adoption, Adjustment [Member]
Balance as of beginning of period	$ 0	2,833
Balance as of end of period		$ 0