Note 4 - Investment Securities - Summary of Amortized Cost and Fair Value by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Due in one year or less	$ 0
Due in one year or less	0
Due after one year through five years	24,517
Due after one year through five years	22,985
Due after five years through ten years	75,811
Due after five years through ten years	67,550
Due after ten years	123,905
Due after ten years	106,641
Total held-to-maturity securities	224,233
Total held-to-maturity securities	197,176
Due in one year or less	750
Due in one year or less	751
Due after one year through five years	26,607
Due after one year through five years	24,238
Due after five years through ten years	30,766
Due after five years through ten years	26,343
Due after ten years	110,191
Due after ten years	99,010
MBS - GSE residential, amortized cost	226,240
MBS - GSE residential, fair value	193,698
Total available-for-sale debt securities	394,554
Total available-for-sale debt securities, fair value	$ 344,040	$ 420,862