Note 5 - Investments, Available-for-sale - Contractual Maturities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Mature in less than one year, amortized cost	$ 84,173
Mature in less than one year, fair value	83,360
Mature in one to two years, amortized cost	9,712
Mature in one to two years, fair value	9,581
Total, amortized cost	93,885	$ 117,944
Total, fair value	$ 92,941	$ 117,697