Investments - Schedule of Equity Investments (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	$ 232	$ 212
Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	620	610
American Airlines, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	232	212
American Airlines, Inc. | Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 620	$ 610
China Southern Airlines
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Ownership interest, fair value method investments	1.50%	1.50%
Carrying value, fair value method investments	$ 153	$ 176
China Southern Airlines | American Airlines, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Ownership interest, fair value method investments	1.50%	1.50%
Carrying value, fair value method investments	$ 153	$ 176
Republic Airline Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Ownership interest, equity method investments	25.00%	25.00%
Carrying value, equity method investments	$ 235	$ 222
Republic Airline Inc. | American Airlines, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Ownership interest, equity method investments	25.00%	25.00%
Carrying value, equity method investments	$ 235	$ 222