Transactions with Related Parties - Vessels Charter Hire and Management Fees (Details) - USD ($) |
8 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
Aug. 30, 2019 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Voyage expenses | $ 0 | $ 0 | $ 651,000 | |
| Proceeds From Divestiture Of Businesses Net Of Transaction Costs | (1,912,000) | |||
| Proceeds from Divestiture of Businesses | $ 0 | 3,000,000 | 0 | |
| NSM | ||||
| Voyage expenses | $ 149,184,000 | 206,427,000 | ||
| Other income/ (expense), net | 15,750,000 | $ 0 | ||
| Administrative services agreement term in years | 5 years | |||
| NSM | Management agreement | ||||
| Termination date of the administrative services agreement | Aug. 29, 2024 | |||
| Management fees | $ 45,487,000 | $ 14,372,000 | ||
| NSM | Management agreement | Chartered-in vessels | ||||
| Daily management fee | 30 | |||
| NSM | The Transaction | ||||
| Proceeds from Divestiture of Businesses | $ 20,000,000 | |||
| NSM | Owned Vessels | Management agreement | ||||
| Daily management fee | $ 3,700 | |||
| NSM | Owned Vessels | Management agreement | After two years | ||||
| Rate of annual increase in management fees | 3.00% | |||