Note 5 - Investments, Available-for-sale - Contractual Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Mature in less than one year, amortized cost	$ 64,662
Mature in less than one year, fair value	64,195
Mature in one to two years, amortized cost	3,902
Mature in one to two years, fair value	3,865
Total, amortized cost	68,564	$ 117,944
Total, fair value	$ 68,060	$ 117,697