Note 13 - Income Taxes - NOL Carryforwards (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Balance at December 31, 2022	$ 28,640	$ 50,771
Net operating losses used and expired	(4,739)	(22,131)
Balance at December 31, 2023	23,901	28,640
Pre-Ownership Change [Member]
Balance at December 31, 2022	4,509	5,147
Net operating losses used and expired	(638)	(638)
Balance at December 31, 2023	3,871	4,509
Post-ownership change [Member]
Balance at December 31, 2022	24,131	45,624
Net operating losses used and expired	(4,101)	(21,493)
Balance at December 31, 2023	$ 20,030	$ 24,131