Condensed Consolidated Statements of Stockholders' Deficit - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Loss	Retained Earnings (Deficit)	Retained Earnings (Deficit) Cumulative Effect, Period of Adoption, Adjustment	American Airlines, Inc.	American Airlines, Inc. Common Stock	American Airlines, Inc. Additional Paid-in Capital	American Airlines, Inc. Accumulated Other Comprehensive Loss	American Airlines, Inc. Retained Earnings (Deficit)
Beginning Balance at Dec. 31, 2019	$ (118)		$ 4	$ 3,945		$ (6,331)	$ 2,264		$ 13,422	$ 0	$ 16,903	$ (6,423)	$ 2,942
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(2,241)						(2,241)		(2,169)				(2,169)
Other comprehensive income, net	(149)					(149)			(149)			(149)
Purchase and retirement of AAG common stock	(145)			(145)
Dividends declared on AAG common stock	(44)						(44)
Issuance of shares of AAG common stock pursuant to employee stock plans net of shares withheld for cash taxes	(13)			(13)
Settlement of single-dip unsecured claims held in Disputed Claims Reserve	56			56
Share-based compensation expense	18			18					18		18
Intercompany equity transfer									56		56
Ending Balance at Mar. 31, 2020	(2,636)		4	3,861		(6,480)	(21)		11,178	0	16,977	(6,572)	773
Beginning Balance at Dec. 31, 2020	(6,867)	$ (301)	6	6,894	$ (320)	(7,103)	(6,664)	$ 19	4,348	0	17,050	(7,194)	(5,508)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(1,250)						(1,250)		(1,215)
Other comprehensive income, net	$ 67					67			66			66
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate202006Member
Issuance of AAG common stock pursuant to an at-the-market offering, net of offering	$ 316			316
Issuance of PSP2 Warrants (see Note 1(b))	65			65
Issuance of shares of AAG common stock pursuant to employee stock plans net of shares withheld for cash taxes	(13)			(13)
Share-based compensation expense	38			38					38		38
Ending Balance at Mar. 31, 2021	$ (7,945)		$ 6	$ 6,980		$ (7,036)	$ (7,895)		$ 3,237	$ 0	$ 17,088	$ (7,128)	$ (6,723)