Fair Value Measurements - Schedule of Carrying Value and Estimated Fair Value of Long-Term Debt, Including Current Maturities (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, including current maturities	$ 24,559	$ 23,779
Fair Value [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, including current maturities	25,334	23,775
American Airlines, Inc. [Member] | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, including current maturities	22,538	22,503
American Airlines, Inc. [Member] | Fair Value [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, including current maturities	$ 23,277	$ 22,497