Note 8 - Assets Held for Sale, Asset Sales and Asset Impairments - Summary of Vessel Sales and Gains on Sales of Vessels (Details) $ in Thousands	12 Months Ended
Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Gain on sale of vessels	$ 15,762	$ 8,701	$ 250
Total vessels sold/recycled	6	7	12
Vessels Held for Sale [Member]
Gain on sale of vessels	$ 0	$ 3,088	$ 5
Vessels sold/recycled from assets held for sale	(0)	8	12
Vessels, Active Fleet [Member]
Vessels sold from active fleet	6	7	2
Gain on sale of vessels	$ 15,677	$ 5,613	$ 553
Vessel [Member]
Gain on sale of vessels	$ 15,677	$ 8,701	$ 558
Total vessels sold/recycled	6	15	14

Amount of gain (loss) on sale or disposal of property, plant and equipment assets, excluding oil and gas property and timber property.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482130/360-10-45-5

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482099/360-10-50-3

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