Note 5 - Investments - Net Gain (Losses) (Details) - USD ($) $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2023	[2]	Sep. 30, 2023	[2]	Jun. 30, 2023	[2]	Mar. 31, 2023	[2]	Dec. 31, 2022	[2]	Sep. 30, 2022	[2]	Jun. 30, 2022	[2]	Mar. 31, 2022	[2]	Dec. 31, 2023	Dec. 31, 2022
Marketable securities (a)	[1]																	$ 384	$ (4,747)
Net gains (losses)		$ 0		$ (4)		$ 43		$ 345		$ (298)		$ (2,121)		$ (2,373)		$ 45		$ 384	$ (4,747)

[1] During 2023, the Company sold its investments in mutual funds managed by GAMCO Investors, Inc. as well as 198,250 shares of IronNet, Inc.

[2] During Q1 and Q2 2023, the net gains primarily relate to the sale of our investments in mutual funds managed by GAMCO Investors, Inc.