Note 3 - Securities (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Securities, Available-for-Sale, Restricted	$ 202,000	$ 118,900
Federal Home Loan Bank Letters of Credit Used as Additional Collateral Amount	$ 210,000	170,000
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions	312
Federal Reserve Bank Stock	$ 6,600	6,500
Federal Home Loan Bank Stock	4,000	6,100
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0	0
Proceeds from Sale of Debt Securities, Available-for-Sale	13,180	0	$ 561
Debt Securities, Available-for-Sale, Realized Gain	55	0	35
Debt Securities, Available-for-Sale, Realized Loss	123	(0)	(0)
Debt Securities, Available-for-Sale, Realized Gain (Loss)	$ (68)	$ (0)	$ 35
US Treasury Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	19
US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	38
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions	37
Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	131
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions	121
Collateralized Mortgage-Backed Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	53
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	59
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions	57
Corporate Debt Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	12