Commitments and Contingencies - Future Commitments to Pay for Usage of Port Facilities (Details) - Port Facility Commitments $ in Thousands |
Dec. 31, 2019
USD ($)
|
|---|---|
| Other Commitments [Line Items] | |
| 2020 | $ 79,418 |
| 2021 | 67,671 |
| 2022 | 68,049 |
| 2023 | 70,100 |
| 2024 | 75,112 |
| Thereafter | 1,726,575 |
| Total minimum annual payments | $ 2,086,925 |