Note 4 - Property and Equipment - Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property and equipment, gross	$ 820,101	$ 790,139
Less: Accumulated depreciation	(294,099)	(250,733)
Property and equipment, net	526,002	539,406
Vessels and Vessel Improvements [Member]
Property and equipment, gross	776,622	759,981
Furniture and Fixtures [Member]
Property and equipment, gross	42,055	28,732
Leasehold Improvements [Member]
Property and equipment, gross	$ 1,424	$ 1,426