Revenue Recognition - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2026	Dec. 31, 2025
Disaggregation of Revenue [Line Items]
Air traffic liability balance	$ 500	$ 361
Air traffic liability recognized as passenger revenue (in percent)	94.00%
Proceeds from prepaid loyalty program consideration	$ 175
Unearned Membership Fees
Disaggregation of Revenue [Line Items]
Air traffic liability balance	$ 81	$ 75

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details