Note 3 - Investment Securities (Details Textual) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Debt Securities, Trading, and Equity Securities, FV-NI, Total	$ 0
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	784
Debt Securities, Available-for-Sale, Unrealized Loss Position, Percent of Securities Cost Basis	13.90%
Debt Securities, Available-for-Sale, Unrealized Loss Position, Percent of Amortized Cost of Investment Securities Portfolio	653.00%
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions	784
Debt Securities, Accrued Interest, after Allowance for Credit Loss	$ 1,700	$ 1,700
Equity Securities, FV-NI, Cost	14,938	27,254
Equity Securities, Held In Correspondent Banks [Member]
Equity Securities, FV-NI, Cost	13,800	26,000
Marketable Securities and Mutual Funds [Member]
Equity Securities, FV-NI, Cost	1,100	1,200
Asset Not Pledged as Collateral and Asset Pledged as Collateral without Right [Member]
Debt Securities	$ 357,000	$ 165,700