Note 1 - Nature of Operations and Summary of Significant Accounting Policies - Property Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Vessels and related equipment	$ 1,070,821	$ 898,649
Other properties and equipment	35,819	19,625
Property, Plant and Equipment, Gross, Ending Balance	1,106,640	918,274
Less accumulated depreciation and amortization	309,985	230,234
Net properties and equipment	$ 796,655	$ 688,040

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation of tangible personal property used to produce goods and services, including, but is not limited to, tools, dies and molds, computer and office equipment.

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Amount before accumulated depreciation, depletion and amortization of other physical assets used in the normal conduct of business to produce goods and services and not intended for resale.

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