REVENUE RECOGNITION - Schedule of Operating Revenue by Geographic Region (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 15,236	$ 14,986	$ 28,448	$ 27,525
Domestic (U.S. and Canada)
Disaggregation of Revenue [Line Items]
Total operating revenue	8,784	8,761	16,818	16,434
Atlantic
Disaggregation of Revenue [Line Items]
Total operating revenue	3,370	3,277	5,270	5,110
Latin America
Disaggregation of Revenue [Line Items]
Total operating revenue	1,362	1,346	2,919	2,791
Pacific
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 1,720	$ 1,602	$ 3,442	$ 3,190

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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- Definition

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