Note 4 - Investments - Details Investments by Major Investment Category (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Gross unrealized losses	$ 77	$ (96)	$ (44)	$ (189)
Amortized costs	5,368		5,368		$ 5,564
Gross unrealized gains	0		0		0
Gross unrealized losses	0		0		0
Total	5,368		5,368		5,564
US Government Agencies Debt Securities [Member]
Amortized costs	4,118		4,118		4,314
Gross unrealized gains	0		0		0
Gross unrealized losses	0		0		0
Total	4,118		4,118		4,314
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Amortized costs	1,000		1,000		1,000
Gross unrealized gains	0		0		0
Gross unrealized losses			0		0
Total	1,000		1,000		1,000
Common Stock [Member]
Amortized costs	250		250		250
Gross unrealized gains	0		0		0
Gross unrealized losses			0		0
Total	$ 250		$ 250		$ 250