Debt - Summary of Availability under Revolving Credit Facilities (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity	$ 7,396
Line of Credit
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity	6,950
Line of Credit | Treasury Loan Agreement
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity	7,000
Proceeds from lines of credit	550
Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity	446
Revolving Credit Facility | Short-term Revolving and Other Facilities
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity	446
American Airlines, Inc. | Line of Credit
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity	6,950
American Airlines, Inc. | Line of Credit | Treasury Loan Agreement
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity	7,500
Proceeds from lines of credit	550
American Airlines, Inc. | Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity	7,396
American Airlines, Inc. | Revolving Credit Facility | Short-term Revolving and Other Facilities
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity	446
American Airlines, Inc. | Revolving Credit Facility | Short Term Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity	400
American Airlines, Inc. | Revolving Credit Facility | Cargo Receivable Facility
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity	$ 46