Revenue - Air Traffic Liability Breakout (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Air traffic liability - passenger travel and ancillary passenger services	$ 4,007	$ 3,061
Air traffic liability - loyalty program	5,190	5,189	$ 4,884	$ 4,789
Total Air traffic liability	$ 9,197	$ 8,250	$ 8,610	$ 7,725