Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Accounts receivable, reserve	$ 2,916	$ 3,169
Accumulated depreciation, vessels	301,694	261,725
Accumulated amortization, other fixed assets	$ 1,393	$ 1,623
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	25,000,000	25,000,000
Preferred stock, issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	700,000,000	700,000,000
Common stock, issued (in shares)	9,326,231	13,003,702
Common stock, outstanding (in shares)	9,326,231	13,003,702