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Revenue - Roll Forward of Frequent Flyer Deferred Revenue (Details) - Frequent Flyer - USD ($) $ in Millions | 3 Months Ended
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Mar. 31, 2024 | Mar. 31, 2023
Frequent Flyer Deferred Revenue [Roll Forward] |  |
Total Frequent flyer deferred revenue - beginning balance | $ 7,143 | $ 6,675
Total miles awarded | 840 | 747
Travel miles redeemed | (665) | (531)
Non-travel miles redeemed | (39) | (31)
Total Frequent flyer deferred revenue - ending balance | $ 7,279 | $ 6,860

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- Details
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