REVENUE - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) performanceObligation	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jul. 28, 2022 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from contract with customer, number of performance obligations | performanceObligation	2
Modification of contract				$ 1,900
Total operating revenues	$ 27,483	$ 26,091	$ 23,814
Residual travel funds (as a percent)	8.00%	8.00%
Loyalty points, redemption period (in years)	1 year
Warranty Obligations
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total operating revenues	$ (116)
Other Revenue
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total operating revenues	$ 2,200	$ 2,100	$ 2,100