Note 8 - Assets Held for Sale, Asset Sales and Asset Impairments (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Number of Vessels Sold	6	7	12
Number of Vessels, Held for Sale, Addition			3
Number of Vessels, Transfer from Held for Sale to Active Fleet		8	1
Number of Vessels, Held for Sale	0	0	8
Proceeds from Sale of Vessels and Other Assets	$ 19,300	$ 15,500	$ 13,600
Impairment Charge Recaptured			500
Asset Impairment Charges, Total	0	0	714
Vessel, Obsolete Inventory [Member]
Asset Impairment Charges, Total	$ 0	$ 0	$ 1,200