Revenue - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue From Contract With Customer [Line Items]
Total operating revenue	$ 14,178	$ 12,112	$ 25,607	$ 19,678
Advance Ticket Sales
Revenue From Contract With Customer [Line Items]
Revenue recognized			4,600	2,600
Ancillary Fees
Revenue From Contract With Customer [Line Items]
Total operating revenue	1,000	900	1,900	1,500
Other Operating Revenue
Revenue From Contract With Customer [Line Items]
Total operating revenue	814	709	1,571	1,300
Other Operating Revenue | Chase and Other Partner Agreements
Revenue From Contract With Customer [Line Items]
Total operating revenue	$ 700	$ 600	$ 1,300	$ 1,100