Basis of Presentation and Summary of Significant Accounting Policies - Significant Contract Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Contract balances, liability	$ 13,423	$ 12,878
Loyalty program [Member]
Disaggregation of Revenue [Line Items]
Contract balances, liability	8,615	8,539
Air traffic [Member]
Disaggregation of Revenue [Line Items]
Contract balances, liability	4,808	4,339
American Airlines, Inc. [Member]
Disaggregation of Revenue [Line Items]
Contract balances, liability	13,423	12,878
American Airlines, Inc. [Member] | Loyalty program [Member]
Disaggregation of Revenue [Line Items]
Contract balances, liability	8,615	8,539
American Airlines, Inc. [Member] | Air traffic [Member]
Disaggregation of Revenue [Line Items]
Contract balances, liability	$ 4,808	$ 4,339