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Total costs of sales and operating expenses for the period.

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REVENUE FROM CONTRACTS WITH CUSTOMERS - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Deferred Revenue Arrangement [Line Items]
Receivable	$ 351		$ 351		$ 296
Costs and Expenses	2,501	$ 2,471	4,883	$ 4,354
Mileage Plan Revenue [Member]
Deferred Revenue Arrangement [Line Items]
Contract liability revenue recognized			602	518
Receivable	96		96		$ 83
Mileage Plan Revenue [Member] \| Mileage plan other revenue [Member]
Deferred Revenue Arrangement [Line Items]
Contract liability revenue recognized			(52)	(26)
Passenger Revenue [Member]
Deferred Revenue Arrangement [Line Items]
Contract liability revenue recognized	$ 103	$ 132	$ 588	$ 522