Basis of Presentation and Summary of Significant Accounting Policies - Operating Property and Equipment (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Depreciation	$ 2,400	$ 2,600	$ 2,400
Impairment charge	$ 1,500
Minimum | Aircraft, engines and related rotable parts
Property, Plant and Equipment [Line Items]
Residual value percentage of equipment and properties	5.00%
Estimated useful life	20 years
Minimum | Buildings and improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Minimum | Furniture, fixtures and other equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum | Capitalized software
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Maximum | Aircraft, engines and related rotable parts
Property, Plant and Equipment [Line Items]
Residual value percentage of equipment and properties	10.00%
Estimated useful life	30 years
Maximum | Buildings and improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	30 years
Maximum | Furniture, fixtures and other equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Maximum | Capitalized software
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Prepaid Expenses and Other Current Assets
Property, Plant and Equipment [Line Items]
Retired aircraft to be sold	$ 164
Other Assets
Property, Plant and Equipment [Line Items]
Nonoperating retired aircraft	401
American Airlines, Inc.
Property, Plant and Equipment [Line Items]
Depreciation	2,300	$ 2,500	$ 2,400
Impairment charge	$ 1,500
American Airlines, Inc. | Minimum | Aircraft, engines and related rotable parts
Property, Plant and Equipment [Line Items]
Residual value percentage of equipment and properties	5.00%
Estimated useful life	20 years
American Airlines, Inc. | Minimum | Buildings and improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
American Airlines, Inc. | Minimum | Furniture, fixtures and other equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
American Airlines, Inc. | Minimum | Capitalized software
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
American Airlines, Inc. | Maximum | Aircraft, engines and related rotable parts
Property, Plant and Equipment [Line Items]
Residual value percentage of equipment and properties	10.00%
Estimated useful life	30 years
American Airlines, Inc. | Maximum | Buildings and improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	30 years
American Airlines, Inc. | Maximum | Furniture, fixtures and other equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
American Airlines, Inc. | Maximum | Capitalized software
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
American Airlines, Inc. | Prepaid Expenses and Other Current Assets
Property, Plant and Equipment [Line Items]
Retired aircraft to be sold	$ 164
American Airlines, Inc. | Other Assets
Property, Plant and Equipment [Line Items]
Nonoperating retired aircraft	$ 400