Revenue Recognition - Revenue Recognized By Revenue (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Revenue from Contract with Customer [Abstract]
Passenger travel	$ 2,418	$ 1,993	$ 6,576	$ 5,786
Loyalty revenue - air transportation	182	142	559	498
Loyalty and related revenue	148	133	436	382
Other revenue	64	54	178	152
Total operating revenue	$ 2,812	$ 2,322	$ 7,749	$ 6,818

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details