Note 8 - Derivatives and Hedging Activities - Hedged Interest Rate Swaps and Non-hedged Interest Rate Swaps (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Swapped loan portfolio loan-to-value percentage, including the potential swap exposure	65.00%
Interest rate swaps
Derivative [Line Items]
Interest rate swaps collateralized by investment securities	$ 150,102	$ 38,756
Interest rate swaps | Cash
Derivative [Line Items]
Interest rate swaps collateralized by investment securities	51,680	1,272
Interest rate swaps | U.S treasuries and govt. sponsored agency securities
Derivative [Line Items]
Interest rate swaps collateralized by investment securities	6,413
Interest rate swaps | Municipal securities.
Derivative [Line Items]
Interest rate swaps collateralized by investment securities	68,651	8,227
Interest rate swaps | Residential mortgage-backed and related securities
Derivative [Line Items]
Interest rate swaps collateralized by investment securities	23,358	$ 29,257
Collateral Pledged
Derivative [Line Items]
Interest rate swaps collateralized by investment securities	$ 10,100