Revenue - Air Traffic Liability Rollforward (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Change in Contract With Customer, Liability [Roll Forward]
Beginning balance	$ 8,250	$ 7,725
Current period sales (passenger travel, ancillary services, flight loyalty, and partner loyalty)	6,072	5,038
Revenue from amounts included in contract liability opening balances	(2,568)	(1,881)
Revenue from current period sales	(2,557)	(2,272)
Ending balance	$ 9,197	$ 8,610