Revenue - Roll Forward of Frequent Flyer Deferred Revenue (Details) - Frequent Flyer - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2024 |
Sep. 30, 2023 |
Sep. 30, 2024 |
Sep. 30, 2023 |
|
| Frequent Flyer Deferred Revenue [Roll Forward] | ||||
| Total Frequent flyer deferred revenue - beginning balance | $ 7,353 | $ 7,024 | $ 7,143 | $ 6,675 |
| Total miles awarded | 884 | 816 | 2,643 | 2,465 |
| Travel miles redeemed | (842) | (740) | (2,325) | (1,983) |
| Non-travel miles redeemed | (24) | (24) | (90) | (81) |
| Total Frequent flyer deferred revenue - ending balance | $ 7,371 | $ 7,076 | $ 7,371 | $ 7,076 |