Note 5 - Investments - Details of Marketable Securities (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Investment Owned, Fair Value		$ 22	$ 16,585
Basis		34	21,297
Cumulative unrealized (loss) gain		(12)	(4,712)
Equity Securities [Member]
Investment Owned, Fair Value	[1]	22	69
Basis	[1]	34	4,307
Cumulative unrealized (loss) gain	[1]	(12)	(4,238)
Mutual Fund [Member]
Investment Owned, Fair Value	[2]	0	16,516
Basis	[2]	0	16,990
Cumulative unrealized (loss) gain	[2]	$ 0	$ (474)

[1] As of December 31, 2022, included the Company's investment in IronNet, Inc., which had a fair value of $46 and a cost basis of $4,273.

[2] As of December 31, 2023, the Company did not have any investments in mutual funds managed by GAMCO Investors, Inc. included in Marketable securities. As of December 31, 2022, the Company had investments in 2 mutual funds managed by GAMCO Investors, Inc. included in Marketable securities.