Note 5 - Investments, Available-for-sale - Contractual Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Mature in less than one year, amortized cost	$ 37,897
Mature in less than one year, fair value	37,697
Mature in one to two years, amortized cost	956
Mature in one to two years, fair value	958
Total, amortized cost	38,853	$ 68,564
Total, fair value	$ 38,655	$ 68,060