Commitments and Contingencies - Aircraft Purchase Commitments by Period (Details) $ in Millions |
Dec. 31, 2019
USD ($)
|
|---|---|
| Future aircraft purchase commitments | |
| Future Purchase Commitments | |
| 2020 | $ 2,980 |
| 2021 | 3,740 |
| 2022 | 3,390 |
| 2023 | 1,640 |
| 2024 | 500 |
| Thereafter | 1,440 |
| Total | 13,690 |
| Capacity purchase agreements | |
| Future Purchase Commitments | |
| 2020 | 1,750 |
| 2021 | 1,432 |
| 2022 | 1,377 |
| 2023 | 1,132 |
| 2024 | 1,002 |
| Thereafter | 2,349 |
| Total | $ 9,042 |