Revenue - Passenger Revenue Breakout (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Operating revenue	$ 7,354	$ 7,037	$ 13,683	$ 12,743
Passenger
Disaggregation of Revenue [Line Items]
Operating revenue	6,712	6,409	12,424	11,514
Passenger non-loyalty
Disaggregation of Revenue [Line Items]
Operating revenue	5,544	5,183	10,224	9,265
Passenger loyalty - air transportation
Disaggregation of Revenue [Line Items]
Operating revenue	895	989	1,694	1,814
Passenger ancillary sold separately
Disaggregation of Revenue [Line Items]
Operating revenue	$ 273	$ 237	$ 506	$ 435

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.

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