Fair Value Measurements - Schedule of Carrying Value and Estimated Fair Value of Long-Term Debt, Including Current Maturities (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, including current maturities	$ 31,110	$ 32,396
Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, including current maturities	30,924	32,310
American Airlines, Inc. | Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, including current maturities	25,884	27,177
American Airlines, Inc. | Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, including current maturities	$ 26,040	$ 27,008