REVENUE - Air Traffic Liability Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Air traffic liability
Beginning balance	$ 7,725	$ 7,133
Current period sales (passenger travel, ancillary services, flight loyalty, and partner loyalty)	22,012	14,702
Revenue from amounts included in contract liability opening balances	(4,976)	(2,945)
Revenue from current period sales	(16,511)	(11,165)
Ending balance	$ 8,250	$ 7,725