Accumulated Other Comprehensive Loss - Reclassifications out of AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Nonoperating other income (expense), net	$ 258	$ 341
Net income (loss)	1,250	2,241
American Airlines, Inc.
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Nonoperating other income (expense), net	215	261
Net income (loss)	1,215	2,169
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	40	(9)
Reclassification out of Accumulated Other Comprehensive Income | Prior service cost (benefit)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Nonoperating other income (expense), net	3	(36)
Reclassification out of Accumulated Other Comprehensive Income | Actuarial loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Nonoperating other income (expense), net	37	27
Reclassification out of Accumulated Other Comprehensive Income | American Airlines, Inc.
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	39	(9)
Reclassification out of Accumulated Other Comprehensive Income | American Airlines, Inc. | Prior service cost (benefit)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Nonoperating other income (expense), net	3	(36)
Reclassification out of Accumulated Other Comprehensive Income | American Airlines, Inc. | Actuarial loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Nonoperating other income (expense), net	$ 36	$ 27