Note 5 - Investment in Unconsolidated Affiliates - Company Operations Due to Affiliates (Details) - Sonatide [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Due to Sonatide at beginning of year		$ 0	$ 40,432	$ 32,767
Plus commissions payable to Sonatide		0	0	3,832
Plus amounts paid by Sonatide on behalf of the company		0	0	10,914
Less amounts used to offset Due from Sonatide obligations (A)	[1]	0	0	(8,530)
Write off of due to affiliate in connection with the acquisition		0	(40,432)	0
Other		0	0	1,449
Accounts Payable		$ 0	$ 0	$ 40,432

[1] We reduced the respective due from affiliates and due to affiliates balances each period through netting transactions based on agreement with the joint venture.