Note 5 - Investments, Available-for-sale (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Debt Securities, Available-for-Sale	$ 0		$ 0		$ 3,971
Debt Securities, Available-for-Sale, Realized Gain (Loss)	$ 0		$ 0
Proceeds from Sale of Debt Securities, Available-for-Sale		$ 0		$ 0