Note 4 - Investments - Details Investments by Major Investment Category (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Gross unrealized losses	$ (121)	$ (93)
Amortized costs	5,366
Gross unrealized gains	0
Gross unrealized losses	0
Total	5,366		$ 5,564
US Government Agencies Debt Securities [Member]
Amortized costs	4,116
Gross unrealized gains	0
Gross unrealized losses	0
Total	4,116
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Amortized costs	1,000
Gross unrealized gains
Gross unrealized losses
Total	1,000
Common Stock [Member]
Amortized costs	250
Gross unrealized gains	0
Gross unrealized losses	0
Total	$ 250