Basis of Presentation and Summary of Significant Accounting Policies - Operating Property and Equipment (Detail) - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Depreciation	$ 2.4	$ 2.2	$ 1.9
Minimum [Member] | Aircraft, engines and related rotable parts [Member]
Property, Plant and Equipment [Line Items]
Residual value percentage of equipment and properties	5.00%
Estimated useful life	20 years
Minimum [Member] | Buildings and improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Minimum [Member] | Furniture, fixtures and other equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum [Member] | Capitalized software [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Maximum [Member] | Aircraft, engines and related rotable parts [Member]
Property, Plant and Equipment [Line Items]
Residual value percentage of equipment and properties	10.00%
Estimated useful life	30 years
Maximum [Member] | Buildings and improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	30 years
Maximum [Member] | Furniture, fixtures and other equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Maximum [Member] | Capitalized software [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
American Airlines, Inc. [Member]
Property, Plant and Equipment [Line Items]
Depreciation	$ 2.4	$ 2.1	$ 1.8
American Airlines, Inc. [Member] | Minimum [Member] | Aircraft, engines and related rotable parts [Member]
Property, Plant and Equipment [Line Items]
Residual value percentage of equipment and properties	5.00%
Estimated useful life	20 years
American Airlines, Inc. [Member] | Minimum [Member] | Buildings and improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
American Airlines, Inc. [Member] | Minimum [Member] | Furniture, fixtures and other equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
American Airlines, Inc. [Member] | Minimum [Member] | Capitalized software [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
American Airlines, Inc. [Member] | Maximum [Member] | Aircraft, engines and related rotable parts [Member]
Property, Plant and Equipment [Line Items]
Residual value percentage of equipment and properties	10.00%
Estimated useful life	30 years
American Airlines, Inc. [Member] | Maximum [Member] | Buildings and improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	30 years
American Airlines, Inc. [Member] | Maximum [Member] | Furniture, fixtures and other equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
American Airlines, Inc. [Member] | Maximum [Member] | Capitalized software [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years