Revenue Recognition - Significant Contract Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Contract balances, liability	$ 13,599	$ 12,864
Loyalty program liability [Member]
Disaggregation of Revenue [Line Items]
Contract balances, liability	8,559	8,822
Air traffic liability [Member]
Disaggregation of Revenue [Line Items]
Contract balances, liability	5,040	4,042
American Airlines, Inc. [Member]
Disaggregation of Revenue [Line Items]
Contract balances, liability	13,599	12,864
American Airlines, Inc. [Member] | Loyalty program liability [Member]
Disaggregation of Revenue [Line Items]
Contract balances, liability	8,559	8,822
American Airlines, Inc. [Member] | Air traffic liability [Member]
Disaggregation of Revenue [Line Items]
Contract balances, liability	$ 5,040	$ 4,042