Basis of Presentation (Details) $ in Millions		3 Months Ended			6 Months Ended
	Dec. 31, 2022 flight	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)
Reclassification [Line Items]
Customer reimbursements other expenses			$ 55
Net income		$ 683		$ 760	$ 524	$ 482
Loss on extinguishment of debt		0		43	0	116
Other (gains) losses, net		$ (7)		25	$ (21)	96
Number of Cancelled Flights | flight	16,700
Revision of Prior Period, Reclassification, Adjustment
Reclassification [Line Items]
Loss on extinguishment of debt				43		116
Other (gains) losses, net				$ 43		$ 116