Note 4 - Investment Securities - Summary of Amortized Cost and Fair Value by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 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	18,777
Due after one year through five years	17,246
Due after five years through ten years	71,172
Due after five years through ten years	62,607
Due after ten years	133,530
Due after ten years	112,231
Total held-to-maturity securities	223,479
Total held-to-maturity securities	192,084
Due in one year or less	751
Due in one year or less	752
Due after one year through five years	21,252
Due after one year through five years	18,951
Due after five years through ten years	36,879
Due after five years through ten years	30,903
Due after ten years	146,077
Due after ten years	128,327
MBS - GSE residential, amortized cost	237,397
MBS - GSE residential, fair value	201,852
Total available-for-sale debt securities, amortized cost	442,356	$ 488,741
Total available-for-sale debt securities, fair value	$ 380,785	$ 420,862