Note 14 - Asset Dispositions, Assets Held for Sale and Asset Impairments - Activity in Assets Held for Sale (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)
Beginning balance	8
Sales	(5)
Ending balance	3
Vessels Held for Sale [Member]
Beginning balance	8	18
Beginning balance	$ 4,195	$ 14,421
Sales	(5)	(5)
Sales	$ (3,500)	$ (4,330)
Transfers	0	(1)
Transfers	$ 0	$ (1,500)
Ending balance	3	12
Ending balance	$ 695	$ 8,591