Note 2 - Debt Securities (Details Textual) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Held-to-Maturity, Allowance for Credit Loss	$ 0	$ 0
US Treasury Securities and Residential Mortgage-Backed Securities [Member]
Debt Securities, Held-to-Maturity, Allowance for Credit Loss	0	0
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Held-to-Maturity, Allowance for Credit Loss		0	$ 0
Asset Not Pledged as Collateral and Asset Pledged as Collateral without Right [Member]
Debt Securities	$ 1,430,000	$ 1,490