Debt - Narrative (Details)			1 Months Ended			2 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 25, 2020 USD ($)	Apr. 30, 2020 USD ($)	Jun. 30, 2020 USD ($) $ / shares	Apr. 30, 2020 USD ($)	Jan. 31, 2020 USD ($)	May 31, 2020 USD ($)	Sep. 30, 2020 USD ($) Aircraft borrowing	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) Aircraft borrowing	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) Aircraft	Oct. 21, 2020 USD ($)	Sep. 29, 2020 USD ($)	Mar. 31, 2020 USD ($)	Feb. 29, 2020 USD ($)	Aug. 31, 2019 USD ($) Aircraft
Debt Instrument [Line Items]
Line of credit facility, remaining borrowing capacity							$ 5,327,000,000		$ 5,327,000,000
Proceeds from issuance of long-term debt									11,564,000,000	$ 3,550,000,000
Costs of issuance									$ 132,000,000	51,000,000
Effective interest rate							20.00%		20.00%
Interest expense							$ 340,000,000	$ 284,000,000	$ 851,000,000	830,000,000
Payroll Support Program Promissory Note
Debt Instrument [Line Items]
Aggregate principal issued							$ 1,800,000,000		$ 1,800,000,000				$ 1,700,000,000
Payroll Support Program Promissory Note | United States Government, CARES Act, Payroll Support Program
Debt Instrument [Line Items]
Increase in debt instrument face amount for each disbursement received		30.00%
Secured Debt | 2014 Credit Facilities
Debt Instrument [Line Items]
Variable interest rate							1.90%		1.90%
Secured Debt | 2013 Credit Facilities
Debt Instrument [Line Items]
Variable interest rate							1.89%		1.89%
Secured Debt | April 2016 Credit Facilities
Debt Instrument [Line Items]
Variable interest rate							2.15%		2.15%
Secured Debt | 11.75% Senior Notes
Debt Instrument [Line Items]
Stated interest rate							11.75%		11.75%
Secured Debt | 10.75% Senior Secured Notes, IP Notes
Debt Instrument [Line Items]
Stated interest rate							10.75%		10.75%
Secured Debt | 10.75% Senior Secured Notes, LGA/DCA Notes
Debt Instrument [Line Items]
Stated interest rate							10.75%		10.75%
Secured Debt | Equipment Loans and Other Notes Payable
Debt Instrument [Line Items]
Average interest rate							1.88%		1.88%
Senior Notes | 6.50% Senior Notes
Debt Instrument [Line Items]
Stated interest rate			6.50%
Aggregate principal issued			$ 1,000,000,000.0				$ 1,000,000,000		$ 1,000,000,000
Issuance price percentage			100.00%
Debt redemption price percentage			100.00%
Proceeds from issuance of long-term debt			$ 970,000,000
Conversion ratio			0.0617284
Conversion price (in dollars per share) | $ / shares			$ 16.20
Conversion terms, percentage sales price exceeds conversion price			130.00%
Measurement period threshold trading price percentage			98.00%
Percent of holders that may declare debt due and payable			25.00%
Interest expense							30,000,000
Amortization of debt discount							14,000,000
Contractual coupon interest							16,000,000
Expected amortization of debt discount, 2020							13,000,000		13,000,000
Expected amortization of debt discount, 2021							63,000,000		63,000,000
Expected amortization of debt discount, 2022							77,000,000		77,000,000
Expected amortization of debt discount, 2023							95,000,000		95,000,000
Expected amortization of debt discount, 2024							116,000,000		116,000,000
Expected amortization of debt discount, 2025							66,000,000		66,000,000
Senior Notes | 3.75% Senior Notes
Debt Instrument [Line Items]
Stated interest rate															3.75%
Aggregate principal issued															$ 500,000,000
Line of Credit
Debt Instrument [Line Items]
Line of credit facility, remaining borrowing capacity							4,927,000,000		4,927,000,000
Line of Credit | Treasury Loan Agreement, CARES Act
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 5,500,000,000						5,500,000,000		5,500,000,000
Borrowings from credit facilities									550,000,000
Line of credit facility, remaining borrowing capacity							$ 4,900,000,000		$ 4,900,000,000
Line of Credit | Secured Debt | Treasury Loan Agreement, CARES Act
Debt Instrument [Line Items]
Variable interest rate							3.73%		3.73%
Other Short-term Revolving Facility
Debt Instrument [Line Items]
Line of credit facility, remaining borrowing capacity							$ 400,000,000		$ 400,000,000
Other Short-term Revolving Facility | Secured Debt | 2014 Credit Facilities
Debt Instrument [Line Items]
Variable interest rate							2.16%		2.16%
Other Short-term Revolving Facility | Secured Debt | 2013 Credit Facilities
Debt Instrument [Line Items]
Variable interest rate							2.16%		2.16%
Other Short-term Revolving Facility | Secured Debt | April 2016 Credit Facilities
Debt Instrument [Line Items]
Variable interest rate							2.16%		2.16%
American Airlines, Inc.
Debt Instrument [Line Items]
Line of credit facility, remaining borrowing capacity							$ 5,327,000,000		$ 5,327,000,000
Proceeds from issuance of long-term debt									8,743,000,000	2,800,000,000
Costs of issuance									122,000,000	41,000,000
Interest expense							$ 310,000,000	$ 281,000,000	$ 825,000,000	$ 835,000,000
American Airlines, Inc. | Secured Debt | 2014 Credit Facilities
Debt Instrument [Line Items]
Variable interest rate							1.90%		1.90%
American Airlines, Inc. | Secured Debt | 2013 Credit Facilities
Debt Instrument [Line Items]
Variable interest rate							1.89%		1.89%
American Airlines, Inc. | Secured Debt | April 2016 Credit Facilities
Debt Instrument [Line Items]
Variable interest rate							2.15%		2.15%
American Airlines, Inc. | Secured Debt | Delayed Draw Term Loan Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity														$ 1,000,000,000.0
American Airlines, Inc. | Secured Debt | 11.75% Senior Notes
Debt Instrument [Line Items]
Stated interest rate							11.75%		11.75%
Issuance price percentage			99.00%
Debt redemption price percentage			100.00%
American Airlines, Inc. | Secured Debt | Special Facility Revenue Bonds
Debt Instrument [Line Items]
Issuance price percentage			98.00%
Proceeds from issuance of long-term debt			$ 353,000,000
Costs of issuance			8,000,000
Repayments of long-term debt			47,000,000
Reimbursement of costs			$ 17,000,000
American Airlines, Inc. | Secured Debt | 5.25% Senior Notes
Debt Instrument [Line Items]
Stated interest rate			5.25%
Aggregate principal issued			$ 214,000,000
American Airlines, Inc. | Secured Debt | 5.375% Senior Notes
Debt Instrument [Line Items]
Stated interest rate			5.375%
Aggregate principal issued			$ 146,000,000
American Airlines, Inc. | Secured Debt | 10.75% Senior Secured Notes, IP Notes
Debt Instrument [Line Items]
Stated interest rate							10.75%		10.75%
American Airlines, Inc. | Secured Debt | 10.75% Senior Secured Notes, LGA/DCA Notes
Debt Instrument [Line Items]
Stated interest rate							10.75%		10.75%
American Airlines, Inc. | Secured Debt | Equipment Loans and Other Notes Payable Maturing 2029 Through 2032
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt									$ 197,000,000
Average interest rate							1.88%		1.88%
American Airlines, Inc. | Secured Debt | Equipment Loans and Other Notes Payable
Debt Instrument [Line Items]
Repayments of long-term debt									$ 17,000,000
Average interest rate							1.88%		1.88%
American Airlines, Inc. | Senior Notes | 11.75% Senior Notes
Debt Instrument [Line Items]
Stated interest rate			11.75%
Aggregate principal issued			$ 2,500,000,000
American Airlines, Inc. | Senior Notes | Special Facility Revenue Bonds
Debt Instrument [Line Items]
Aggregate principal issued			$ 360,000,000
American Airlines, Inc. | Senior Notes | 10.75% Senior Secured Notes
Debt Instrument [Line Items]
Stated interest rate	10.75%
Aggregate principal issued							$ 1,200,000,000		$ 1,200,000,000
Alternative interest rate	0.1200
American Airlines, Inc. | Senior Notes | 10.75% Senior Secured Notes | On or Prior to the Fourth Anniversary
Debt Instrument [Line Items]
Debt redemption price percentage	100.00%
American Airlines, Inc. | Senior Notes | 10.75% Senior Secured Notes | After the Fourth Anniversary and On or Prior to the Fifth Anniversary
Debt Instrument [Line Items]
Debt redemption price percentage	105.375%
American Airlines, Inc. | Senior Notes | 10.75% Senior Secured Notes | In the Event of Specified Change of Control
Debt Instrument [Line Items]
Debt redemption price percentage	101.00%
American Airlines, Inc. | Payment in Kind (PIK) Note | 10.75% Senior Secured Notes, IP Notes
Debt Instrument [Line Items]
Aggregate principal issued	$ 1,000,000,000.0
Additional pari passu debt	4,000,000,000.0
American Airlines, Inc. | Payment in Kind (PIK) Note | 10.75% Senior Secured Notes, LGA/DCA Notes
Debt Instrument [Line Items]
Aggregate principal issued	200,000,000
American Airlines, Inc. | Enhanced Equipment Trust Certificates (EETC)
Debt Instrument [Line Items]
Repayments of long-term debt											$ 608,000,000
American Airlines, Inc. | Enhanced Equipment Trust Certificates (EETC) | Enhanced Equipment Trust Certificates 2019-1
Debt Instrument [Line Items]
Aggregate principal issued																$ 1,100,000,000
Repayments of long-term debt							$ 126,000,000				$ 804,000,000
Number of aircraft financed by debt issuance | Aircraft																35
Number of aircrafts financed through repurchased debt | Aircraft							3		3		28
Remaining escrowed proceeds							$ 168,000,000		$ 168,000,000
American Airlines, Inc. | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, remaining borrowing capacity							4,927,000,000		4,927,000,000
American Airlines, Inc. | Line of Credit | Treasury Loan Agreement, CARES Act
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 5,500,000,000
Borrowings from credit facilities									550,000,000
Line of credit facility, remaining borrowing capacity							$ 4,900,000,000		$ 4,900,000,000
Number of subsequent borrowings | borrowing							2		2
Variable interest rate							3.73%		3.73%
Required collateral coverage ratio	1.6
Current collateral coverage ratio (significantly in excess of)	2.0
Minimum aggregate liquidity	$ 2,000,000,000.0
American Airlines, Inc. | Line of Credit | Treasury Loan Agreement, CARES Act | Subsequent Event
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity												$ 7,500,000,000
American Airlines, Inc. | Line of Credit | Treasury Loan Agreement, CARES Act | Debt Service Coverage Ratio, Scenario One
Debt Instrument [Line Items]
Debt service coverage ratio	1.75
American Airlines, Inc. | Line of Credit | Treasury Loan Agreement, CARES Act | Debt Service Coverage Ratio, Scenario Two
Debt Instrument [Line Items]
Debt service coverage ratio	1.50
American Airlines, Inc. | Line of Credit | Treasury Loan Agreement, CARES Act | Debt Service Coverage Ratio, Scenario Three
Debt Instrument [Line Items]
Debt service coverage ratio	1.25
American Airlines, Inc. | Line of Credit | Treasury Loan Agreement, CARES Act | Escrow Deposit Percentage, Scenario One
Debt Instrument [Line Items]
Percentage of certain revenues in blocked account	0.50
American Airlines, Inc. | Line of Credit | Treasury Loan Agreement, CARES Act | Escrow Deposit Percentage, Scenario Two
Debt Instrument [Line Items]
Percentage of certain revenues in blocked account	0.75
American Airlines, Inc. | Line of Credit | Treasury Loan Agreement, CARES Act | Adjusted LIBOR Rate
Debt Instrument [Line Items]
Basis spread on variable rate									3.50%
American Airlines, Inc. | Line of Credit | Secured Debt | Treasury Loan Agreement, CARES Act
Debt Instrument [Line Items]
Variable interest rate							3.73%		3.73%
American Airlines, Inc. | Other Short-term Revolving Facility
Debt Instrument [Line Items]
Line of credit facility, remaining borrowing capacity							$ 400,000,000		$ 400,000,000
American Airlines, Inc. | Other Short-term Revolving Facility | Other Short-term Revolving Facility
Debt Instrument [Line Items]
Line of credit facility, remaining borrowing capacity							$ 400,000,000		$ 400,000,000
American Airlines, Inc. | Other Short-term Revolving Facility | Secured Debt | 2014 Credit Facilities
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					$ 1,200,000,000
Borrowings from credit facilities						$ 1,600,000,000
Variable interest rate							2.16%		2.16%
American Airlines, Inc. | Other Short-term Revolving Facility | Secured Debt | 2014 Credit Facilities | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate					1.75%						2.00%
Basis spread on variable rate, floor					0.00%
American Airlines, Inc. | Other Short-term Revolving Facility | Secured Debt | 2014 Credit Facilities | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate					0.75%						1.00%
American Airlines, Inc. | Other Short-term Revolving Facility | Secured Debt | 2013 Credit Facilities
Debt Instrument [Line Items]
Borrowings from credit facilities				$ 750,000,000
Line of credit facility, remaining borrowing capacity		$ 0		$ 0		$ 0
Variable interest rate							2.16%		2.16%
American Airlines, Inc. | Other Short-term Revolving Facility | Secured Debt | 2013 Credit Facilities | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate				2.00%
Stated interest rate						2.00%
American Airlines, Inc. | Other Short-term Revolving Facility | Secured Debt | April 2016 Credit Facilities
Debt Instrument [Line Items]
Borrowings from credit facilities				$ 450,000,000
Line of credit facility, remaining borrowing capacity		$ 0		$ 0
Variable interest rate							2.16%		2.16%
American Airlines, Inc. | Other Short-term Revolving Facility | Secured Debt | April 2016 Credit Facilities | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate				2.00%
Interest Rate First Five Years | Payroll Support Program Promissory Note
Debt Instrument [Line Items]
Stated interest rate		1.00%		1.00%
Interest Rate Years Six Through Ten | Payroll Support Program Promissory Note | Secured Overnight Financing Rate
Debt Instrument [Line Items]
Basis spread on variable rate		2.00%
Basis spread on variable rate, floor		0.00%
JFK Airport upgrade | American Airlines, Inc.
Debt Instrument [Line Items]
Construction project investment amount					$ 344,000,000