Note 5 - Acquisitions and Investments - Gains and Losses on Equity Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Net gains and (losses) recognized during the period on equity securities	$ (532)	$ (3,578)	$ (1,832)
Less: Net gains realized during the period on equity securities	0	0	(2,981)
Unrealized net gains and losses recognized during the period on equity securities still held at the reporting date	$ (532)	$ (3,578)	$ (4,813)