Note 7 - Investments - Fixed Maturities by Contractual Maturity Periods (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Due in one year or less	$ 7,163
Due in one year or less, estimated fair value	7,034
Due after one year through five years	26,317
Due after one year through five years, estimated fair value	24,628
Due after five years through ten years	2,239
Due after five years through ten years, estimated fair value	1,982
Due after ten years	4,408
Due after ten years, estimated fair value	3,947
Total	40,127	$ 35,889	$ 35,889
Total, estimated fair value	$ 37,591	$ 35,666	$ 35,666