Note 6 - Investments - Fixed Maturities by Contractual Maturity Periods (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Due in one year or less	$ 7,059
Due in one year or less, estimated fair value	7,096
Due after one year through five years	18,368
Due after one year through five years, estimated fair value	18,404
Due after five years through ten years	5,669
Due after five years through ten years, estimated fair value	5,640
Due after ten years	3,208
Due after ten years, estimated fair value	3,199
Total	34,304	$ 20,488
Total, estimated fair value	$ 34,339	$ 20,716