Revenue - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Revenue Arrangement
Operating Revenue	$ 9,048	$ 22,428	$ 21,965
Residual Travel Funds	28.00%	2.00%
Contract with Customer Liability - Customer Travel Funds	$ 2,100
Contract with Customer, Liability, Current - Customer Travel Funds Expiration Date as of December 31, 2020	Sep. 07, 2022
Chase And Other Partner Agreements
Deferred Revenue Arrangement
Operating Revenue	$ 1,100	$ 1,300	$ 1,100