Note 2 - Securities Available for Sale - Amortized Cost and Fair Value of Investment Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Due within one year, amortized cost	$ 4,144
Due within one year, fair value	4,140
Due after one year through five years, amortized cost	16,550
Due after one year through five years, fair value	16,526
Due after five years through ten years, amortized cost	18,629
Due after five years through ten years, fair value	17,399
Due after ten years, amortized cost	13,150
Due after ten years, fair value	12,558
Amortized cost	223,620	$ 222,665
Fair value	200,440	196,588
Mortgage-related Securities [Member]
Without single date securities	171,072
Without single date securities, fair value	149,742
Amortized cost	171,072	169,915
Fair value	149,742	146,185
Other Securities [Member]
Without single date securities	75
Without single date securities, fair value	75
Amortized cost	75	51
Fair value	$ 75	$ 51