Note 4 - Summary of Unrealized and Realized Gains and Losses Recognized in Net Income on Equity Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Equity Securities [Abstract]
Net gain (loss) recognized during the period on equity securities	$ 231	$ (621)	$ 2,714
Less: Net (loss) gain recognized during the period on equity securities sold during the period	(19)	405	1,788
Net unrealized gain (loss) recognized during the reporting period on equity securities still held at the reporting date	$ 250	$ (1,026)	$ 926