Basis of Presentation and Recent Accounting Pronouncements (Details)	1 Months Ended		3 Months Ended			6 Months Ended
	Apr. 30, 2021 USD ($) shares	Jan. 31, 2021 USD ($)	Jun. 30, 2021 USD ($) $ / shares shares	Mar. 31, 2021 USD ($) member shares	Jun. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($) $ / shares shares	Apr. 23, 2021 $ / shares	Mar. 24, 2021 USD ($)	Jan. 15, 2021 USD ($) $ / shares	Jan. 01, 2021 USD ($)	Dec. 31, 2020 USD ($)	Oct. 21, 2020 USD ($)	Sep. 25, 2020 USD ($)
Unusual or Infrequent Item, or Both [Line Items]
Decrease in flying in percentage			24.60%
Decrease in domestic capacity in percentage			12.80%
Decrease in international capacity in percentage			46.50%
Number of team members opting for early retirement or long-term paid leave | member				1,600
Available liquidity			$ 21,300,000,000				$ 21,300,000,000
Unrestricted cash and short-term investments			18,000,000,000.0				18,000,000,000.0
Line of credit facility, remaining borrowing capacity			3,313,000,000				3,313,000,000
Minimum liquidity			2,000,000,000.0				2,000,000,000.0
Equity component of convertible debt issued, net of tax and offering costs					$ (320,000,000)
Retained deficit			$ (7,876,000,000)				$ (7,876,000,000)					$ (6,664,000,000)
At-The-Market Offering
Unusual or Infrequent Item, or Both [Line Items]
Issuance of shares of AAG common stock pursuant to a public stock offering (in shares) | shares				18,194,573			24,200,000
Price per share (in dollars per share) | $ / shares			$ 19.26				$ 19.26
Proceeds from issuance of common stock							$ 460,000,000
Common stock, remaining authorized amount			$ 650,000,000				650,000,000
US Department of the Treasury, CARES Act, Payroll Support Program Two
Unusual or Infrequent Item, or Both [Line Items]
Financial assistance received under the CARES Act	$ 463,000,000	$ 3,500,000,000	3,100,000,000	$ 3,100,000,000			3,500,000,000
Financial assistance, credit to special items			314,000,000				2,400,000,000
US Department Of The Treasury, CARES Act, Payroll Support Program Three
Unusual or Infrequent Item, or Both [Line Items]
Financial assistance received under the CARES Act			3,300,000,000
Payroll support program grant, deferred in other accrued liabilities			1,100,000,000				1,100,000,000
Financial assistance, credit to special items							1,200,000,000
Payroll Support Program Promissory Note Two, CARES Act
Unusual or Infrequent Item, or Both [Line Items]
Debt instrument, face amount	$ 1,000,000,000.0			$ 1,000,000,000.0						$ 1,000,000,000.0
Warrants, number of warrant shares of common stock | shares	6,600,000			6,600,000
Exercise price of warrants (in dollars per share) | $ / shares										$ 15.66
Payroll Support Program Promissory Note Three, CARES Act
Unusual or Infrequent Item, or Both [Line Items]
Debt instrument, face amount			$ 946,000,000				$ 946,000,000
Warrants, number of warrant shares of common stock | shares			4,400,000				4,400,000
Exercise price of warrants (in dollars per share) | $ / shares								$ 21.75
PSP2 Warrants
Unusual or Infrequent Item, or Both [Line Items]
Warrants, fair value	$ 76,000,000
PSP3 Warrants
Unusual or Infrequent Item, or Both [Line Items]
Warrants, fair value			$ 46,000,000				$ 46,000,000
Other PSP2 Financial Assistance, CARES Act
Unusual or Infrequent Item, or Both [Line Items]
Debt instrument, face amount			2,400,000,000				2,400,000,000
Financial assistance received under the CARES Act				$ 2,400,000,000
Other PSP3 Financial Assistance, CARES Act | Forecast
Unusual or Infrequent Item, or Both [Line Items]
Financial assistance received under the CARES Act						$ 2,300,000,000
Senior Notes | 5.50% Senior Notes
Unusual or Infrequent Item, or Both [Line Items]
Debt instrument, face amount			$ 3,500,000,000				$ 3,500,000,000		$ 3,500,000,000
Stated interest rate			5.50%				5.50%		5.50%
Senior Notes | 5.75% Senior Notes
Unusual or Infrequent Item, or Both [Line Items]
Debt instrument, face amount			$ 3,000,000,000.0				$ 3,000,000,000.0		$ 3,000,000,000.0
Stated interest rate			5.75%				5.75%		5.75%
Senior Notes | 6.50% Senior Notes
Unusual or Infrequent Item, or Both [Line Items]
Debt instrument, face amount			$ 1,000,000,000				$ 1,000,000,000
Stated interest rate					6.50%
Senior Notes | 6.50% Senior Notes | Cumulative Effect, Period of Adoption, Adjustment
Unusual or Infrequent Item, or Both [Line Items]
Equity component of convertible debt issued, net of tax and offering costs							415,000,000
Equity component of convertible debt issued, net of tax and offering costs							$ 320,000,000
Retained deficit											$ 19,000,000
Reduction of unamortized discount											$ 389,000,000
Secured Debt | 5.50% Senior Notes
Unusual or Infrequent Item, or Both [Line Items]
Stated interest rate			5.50%				5.50%
Secured Debt | 5.75% Senior Notes
Unusual or Infrequent Item, or Both [Line Items]
Stated interest rate			5.75%				5.75%
Secured Debt | Term Loan Facility
Unusual or Infrequent Item, or Both [Line Items]
Debt instrument, face amount			$ 3,500,000,000				$ 3,500,000,000
Secured Debt | Special Facility Revenue Bonds
Unusual or Infrequent Item, or Both [Line Items]
Debt instrument, face amount			150,000,000				150,000,000
Repayments of long-term debt							62,000,000
Revolving Credit Facility
Unusual or Infrequent Item, or Both [Line Items]
Line of credit facility, remaining borrowing capacity			2,800,000,000				2,800,000,000
Revolving Credit Facility | Short-term Revolving and Other Facilities
Unusual or Infrequent Item, or Both [Line Items]
Line of credit facility, remaining borrowing capacity			470,000,000				470,000,000
Revolving Credit Facility | 2013 Revolving Facility
Unusual or Infrequent Item, or Both [Line Items]
Line of credit facility, remaining borrowing capacity			750,000,000				750,000,000
Debt instrument, face amount			0				0
Revolving Credit Facility | 2014 Revolving Facility
Unusual or Infrequent Item, or Both [Line Items]
Line of credit facility, remaining borrowing capacity			1,643,000,000				1,643,000,000
Debt instrument, face amount			0				0
Revolving Credit Facility | April 2016 Revolving Facility
Unusual or Infrequent Item, or Both [Line Items]
Line of credit facility, remaining borrowing capacity			450,000,000				450,000,000
Debt instrument, face amount			0				0
American Airlines, Inc.
Unusual or Infrequent Item, or Both [Line Items]
Available liquidity			21,200,000,000				21,200,000,000
Unrestricted cash and short-term investments			17,900,000,000				17,900,000,000
Line of credit facility, remaining borrowing capacity			3,313,000,000				3,313,000,000
Retained deficit			$ (6,672,000,000)				$ (6,672,000,000)					$ (5,508,000,000)
American Airlines, Inc. | Secured Debt | 5.50% Senior Notes
Unusual or Infrequent Item, or Both [Line Items]
Stated interest rate			5.50%				5.50%
American Airlines, Inc. | Secured Debt | 5.75% Senior Notes
Unusual or Infrequent Item, or Both [Line Items]
Stated interest rate			5.75%				5.75%
American Airlines, Inc. | Secured Debt | April 2016 Revolving Facility
Unusual or Infrequent Item, or Both [Line Items]
Line of credit facility, maximum borrowing capacity			$ 450,000,000				$ 450,000,000
American Airlines, Inc. | Secured Debt | Equipment Loans and Other Notes Payable
Unusual or Infrequent Item, or Both [Line Items]
Proceeds from sale-leaseback transactions							163,000,000
American Airlines, Inc. | Revolving Credit Facility
Unusual or Infrequent Item, or Both [Line Items]
Line of credit facility, remaining borrowing capacity			2,800,000,000				2,800,000,000
American Airlines, Inc. | Revolving Credit Facility | Short-term Revolving and Other Facilities
Unusual or Infrequent Item, or Both [Line Items]
Line of credit facility, remaining borrowing capacity			470,000,000				470,000,000
American Airlines, Inc. | Revolving Credit Facility | 2013 Revolving Facility
Unusual or Infrequent Item, or Both [Line Items]
Line of credit facility, remaining borrowing capacity			750,000,000				750,000,000
American Airlines, Inc. | Revolving Credit Facility | 2014 Revolving Facility
Unusual or Infrequent Item, or Both [Line Items]
Line of credit facility, remaining borrowing capacity			1,643,000,000				1,643,000,000
American Airlines, Inc. | Revolving Credit Facility | April 2016 Revolving Facility
Unusual or Infrequent Item, or Both [Line Items]
Line of credit facility, remaining borrowing capacity			450,000,000				450,000,000
American Airlines, Inc. | Revolving Credit Facility | Secured Debt | 2013 Revolving Facility
Unusual or Infrequent Item, or Both [Line Items]
Repayments of long-term debt							750,000,000
American Airlines, Inc. | Revolving Credit Facility | Secured Debt | 2014 Revolving Facility
Unusual or Infrequent Item, or Both [Line Items]
Repayments of long-term debt							1,600,000,000
American Airlines, Inc. | Revolving Credit Facility | Secured Debt | April 2016 Revolving Facility
Unusual or Infrequent Item, or Both [Line Items]
Repayments of long-term debt							450,000,000
American Airlines, Inc. | Line of Credit | Treasury Loan Agreement, CARES Act
Unusual or Infrequent Item, or Both [Line Items]
Repayments of long-term debt							550,000,000
Line of credit facility, maximum borrowing capacity			$ 7,500,000,000				$ 7,500,000,000						$ 7,500,000,000	$ 5,500,000,000