Accumulated Other Comprehensive Loss - Components of AOCI (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
AOCI tax, attributable to parent [Roll Forward]
Beginning balance, tax			$ (865)				$ (865)
Other comprehensive loss before reclassifications, tax							(8)
Amounts reclassified from AOCI, tax							(34)
Net current-period other comprehensive income (loss), tax							(42)
Ending balance, tax	$ (907)						(907)
AOCI attributable to parent, net of tax [Roll Forward]
Beginning balance, net of tax			(7,103)				(7,103)
Other comprehensive loss before reclassifications, net of tax							27
Amounts reclassified from AOCI, net of tax							119
Total other comprehensive income (loss), net of tax	40	$ 39	67	$ (13)	$ 17	$ (149)	146	$ (145)
Ending balance, net of tax	(6,957)						(6,957)
Pension, Retiree Medical and Other Postretirement Benefits
AOCI attributable to parent, before tax [Roll Forward]
Beginning balance, before tax			(6,236)				(6,236)
Other comprehensive loss before reclassifications, before tax							35
Amounts reclassified from AOCI, before tax							153
Net current-period other comprehensive income (loss), before tax							188
Ending balance, before tax	(6,048)						(6,048)
Unrealized Gain (Loss) on Investments
AOCI attributable to parent, before tax [Roll Forward]
Beginning balance, before tax			(2)				(2)
Other comprehensive loss before reclassifications, before tax							0
Amounts reclassified from AOCI, before tax							0
Net current-period other comprehensive income (loss), before tax							0
Ending balance, before tax	(2)						(2)
American Airlines, Inc.
AOCI tax, attributable to parent [Roll Forward]
Beginning balance, tax			(977)				(977)
Other comprehensive loss before reclassifications, tax							(8)
Amounts reclassified from AOCI, tax							(34)
Net current-period other comprehensive income (loss), tax							(42)
Ending balance, tax	(1,019)						(1,019)
AOCI attributable to parent, net of tax [Roll Forward]
Beginning balance, net of tax			(7,194)				(7,194)
Other comprehensive loss before reclassifications, net of tax							27
Amounts reclassified from AOCI, net of tax							118
Total other comprehensive income (loss), net of tax	40	$ 39	66	$ (14)	$ 17	$ (149)	145	$ (146)
Ending balance, net of tax	(7,049)						(7,049)
American Airlines, Inc. | Pension, Retiree Medical and Other Postretirement Benefits
AOCI attributable to parent, before tax [Roll Forward]
Beginning balance, before tax			(6,215)				(6,215)
Other comprehensive loss before reclassifications, before tax							35
Amounts reclassified from AOCI, before tax							152
Net current-period other comprehensive income (loss), before tax							187
Ending balance, before tax	(6,028)						(6,028)
American Airlines, Inc. | Unrealized Gain (Loss) on Investments
AOCI attributable to parent, before tax [Roll Forward]
Beginning balance, before tax			$ (2)				(2)
Other comprehensive loss before reclassifications, before tax							0
Amounts reclassified from AOCI, before tax							0
Net current-period other comprehensive income (loss), before tax							0
Ending balance, before tax	$ (2)						$ (2)