Fair Value of Financial Instruments - Fair Value (Details) - USD ($)
$ in Thousands
Jun. 30, 2022
Dec. 31, 2021
Fair Value Of Financial Instruments    
Cash and cash equivalents - Book Value $ 46,220 $ 53,591
Cash and cash equivalents - Fair Value 46,220 53,591
Restricted cash - Book Value 8,726 84,260
Restricted cash - Fair Value 8,726 84,260
Investments in available-for-sale-securities - Book Value 220 219
Investments in available-for-sale-securities - Fair Value 220 219
Senior and ship mortgage notes, net - Book Value (584,450) (1,101,931)
Senior and ship mortgage notes, net - Fair Value (572,943) (1,142,545)
Long-term debt, including current portion - Book Value (379,374) (171,919)
Long-term debt, including current portion - Fair Value (382,536) (173,213)
Loans payable to affiliate companies, including current portion and Convertible Debenture - Book Value (308,065) (112,634)
Loans payable to affiliate companies, including current portion and Convertible Debenture - Fair Value $ (310,269) $ (112,634)