Note 3 - Securities - Available-for-sale Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
One year or less, amortized cost	$ 13,428
One year or less, fair value	13,257
After one year through five years, amortized cost	82,337
After one year through five years, fair value	75,279
After five years through ten years, amortized cost	92,153
After five years through ten years, fair value	76,522
After ten years, amortized cost	108,736
After ten years, fair value	88,560
Available-for-sale debt securities, amortized cost	508,741	$ 537,912
Available-for-sale debt securities, at fair value	437,142	476,091
Collateralized Mortgage-Backed Securities [Member]
Securities without a single maturity, amortized cost	19,616
Securities without a single maturity, fair value	16,131
Available-for-sale debt securities, amortized cost	19,616	23,332
Available-for-sale debt securities, at fair value	16,131	20,663
Collateralized Mortgage Obligations [Member]
Securities without a single maturity, amortized cost	171,526
Securities without a single maturity, fair value	146,529
Asset-Backed Securities [Member]
Securities without a single maturity, amortized cost	20,945
Securities without a single maturity, fair value	20,864
Available-for-sale debt securities, amortized cost	20,945	15,287
Available-for-sale debt securities, at fair value	$ 20,864	$ 14,941

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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