Basis of Presentation and Summary of Significant Accounting Policies - Regional Expenses (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Regional Expenses [Line Items]
Aircraft fuel and related taxes	$ 2,581	$ 7,526	$ 8,053
Salaries, wages and benefits	10,960	12,609	12,251
Maintenance, materials and repairs	1,583	2,380	2,050
Other rent and landing fees	1,536	2,055	1,900
Aircraft rent	1,341	1,326	1,264
Selling expenses	513	1,602	1,520
Depreciation and amortization	2,040	1,982	1,839
Other	2,969	5,087	5,088
Total regional expenses	$ 4,892	7,501	7,133
Republic Holdings
Regional Expenses [Line Items]
Ownership interest	25.00%
Regional Carrier
Regional Expenses [Line Items]
Aircraft fuel and related taxes	$ 821	1,869	1,843
Salaries, wages and benefits	1,591	1,781	1,591
Capacity purchases from third-party regional carriers	1,054	1,398	1,431
Maintenance, materials and repairs	314	403	340
Other rent and landing fees	496	651	610
Aircraft rent	13	29	32
Selling expenses	153	402	369
Depreciation and amortization	325	336	318
Special items, net	(309)	6	6
Other	434	626	593
Total regional expenses	4,892	7,501	7,133
Regional Carrier \| Republic
Regional Expenses [Line Items]
Capacity purchases from third-party regional carriers	438	590	565
American Airlines, Inc.
Regional Expenses [Line Items]
Aircraft fuel and related taxes	2,581	7,526	8,053
Salaries, wages and benefits	10,955	12,600	12,240
Maintenance, materials and repairs	1,583	2,380	2,050
Other rent and landing fees	1,536	2,055	1,900
Aircraft rent	1,341	1,326	1,264
Selling expenses	513	1,602	1,520
Depreciation and amortization	2,040	1,982	1,839
Other	2,991	5,090	5,090
Total regional expenses	$ 4,676	7,518	7,064
American Airlines, Inc. \| Republic Holdings
Regional Expenses [Line Items]
Ownership interest	25.00%
American Airlines, Inc. \| Regional Carrier
Regional Expenses [Line Items]
Aircraft fuel and related taxes	$ 821	1,869	1,843
Salaries, wages and benefits	275	325	338
Capacity purchases from third-party regional carriers	2,750	3,562	3,267
Maintenance, materials and repairs	3	30	8
Other rent and landing fees	468	621	583
Aircraft rent	13	29	27
Selling expenses	153	402	369
Depreciation and amortization	273	286	267
Special items, net	(338)	0	0
Other	258	394	362
Total regional expenses	4,676	7,518	7,064
American Airlines, Inc. \| Regional Carrier \| Republic
Regional Expenses [Line Items]
Capacity purchases from third-party regional carriers	$ 438	$ 590	$ 565

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Regional Expenses [Line Items]

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Maintenance costs incurred and directly related to services rendered by an entity during the reporting period. Includes the cost of inspections and repairs, materials and routine maintenance costs for all aircraft and engines.

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Fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period.

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Direct costs incurred at airports in which the entity conducts flight operations. The costs primarily consist of fees paid to the airport authority for takeoff and landing, gate space and facilities, allocations of common space such as security and other terminal costs and fuel storage facilities.

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