Note 13 - Accrued Charter Revenue, Current and Non-current, Unearned Revenue, Current and Non-current and Time Charter Assumed, Current and Non-current - Schedule of Unearned Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Unearned Revenue	$ 57,697	$ 41,520
Less current portion	(23,830)	(11,893)
Non-current portion	33,867	29,627
Unearned Revenues Regarding Hires Collected in Advance [Member]
Unearned Revenue	19,173	7,236
Unearned Revenues Regarding Charter Revenues Resulting from Varying Charter Rates [Member]
Unearned Revenue	$ 38,524	$ 34,284