REVENUE RECOGNITION - Narrative (Details) - USD ($) $ in Billions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Revenue from Contract with Customer [Abstract] | |||
| Revenue recognized that was previously recorded in air traffic liability | $ 6.4 | $ 6.5 | $ 7.4 |
| Marketing contracts initial terms, minimum (in years) | 1 year | ||
| Marketing contracts initial terms, maximum (in years) | 13 years | ||
| Cash sales of miles from marketing agreements | $ 8.0 | $ 7.4 | $ 6.9 |
| Majority of new miles, redemption period (in years) | 2 years | ||