Note 4 - Derivatives - Cash Flow Hedges Included in Consolidated Statements of Condition (Details) - Interest Rate Swap [Member] - Cash Flow Hedging [Member] - Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Derivative, notional amount	$ 950,000	$ 950,000
Derivative, fair value	$ 61,972	$ 56,797