Accumulated Other Comprehensive Loss - Components of AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
AOCI tax, attributable to parent [Roll Forward]
Beginning balance, tax	$ (865)
Other comprehensive loss before reclassifications, tax	(8)
Amounts reclassified from AOCI, tax	(11)
Net current-period other comprehensive income (loss), tax	(19)
Ending balance, tax	(884)
AOCI attributable to parent, net of tax [Roll Forward]
Beginning balance, net of tax	(7,103)
Other comprehensive loss before reclassifications, net of tax	27
Amounts reclassified from AOCI, net of tax	40
Total other comprehensive income (loss), net of tax	67	$ (149)
Ending balance, net of tax	(7,036)
Pension, Retiree Medical and Other Postretirement Benefits
AOCI attributable to parent, before tax [Roll Forward]
Beginning balance, before tax	(6,236)
Other comprehensive loss before reclassifications, before tax	35
Amounts reclassified from AOCI, before tax	51
Net current-period other comprehensive income (loss), before tax	86
Ending balance, before tax	(6,150)
Unrealized Gain (Loss) on Investments
AOCI attributable to parent, before tax [Roll Forward]
Beginning balance, before tax	(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)
American Airlines, Inc.
AOCI tax, attributable to parent [Roll Forward]
Beginning balance, tax	(977)
Other comprehensive loss before reclassifications, tax	(8)
Amounts reclassified from AOCI, tax	(11)
Net current-period other comprehensive income (loss), tax	(19)
Ending balance, tax	(996)
AOCI attributable to parent, net of tax [Roll Forward]
Beginning balance, net of tax	(7,194)
Other comprehensive loss before reclassifications, net of tax	27
Amounts reclassified from AOCI, net of tax	39
Total other comprehensive income (loss), net of tax	66	$ (149)
Ending balance, net of tax	(7,128)
American Airlines, Inc. | Pension, Retiree Medical and Other Postretirement Benefits
AOCI attributable to parent, before tax [Roll Forward]
Beginning balance, before tax	(6,215)
Other comprehensive loss before reclassifications, before tax	35
Amounts reclassified from AOCI, before tax	50
Net current-period other comprehensive income (loss), before tax	85
Ending balance, before tax	(6,130)
American Airlines, Inc. | Unrealized Gain (Loss) on Investments
AOCI attributable to parent, before tax [Roll Forward]
Beginning balance, before tax	(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)