Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Operating loss carryforwards and other credits	$ 4,027	$ 2,103
Loyalty program liability	1,977	1,755
Leases	1,913	2,077
Pensions	1,405	1,229
Postretirement benefits other than pensions	203	145
Rent expense	96	126
Reorganization items	28	30
Alternative minimum tax (AMT) credit carryforwards	0	90
Other	847	613
Total deferred tax assets	10,496	8,168
Valuation allowance	(34)	(34)
Net deferred tax assets	10,462	8,134
Deferred tax liabilities:
Accelerated depreciation and amortization	(5,028)	(5,196)
Leases	(1,818)	(1,979)
Other	(386)	(343)
Total deferred tax liabilities	(7,232)	(7,518)
Net deferred tax asset	3,230	616
American Airlines, Inc.
Deferred tax assets:
Operating loss carryforwards and other credits	3,944	2,115
Loyalty program liability	1,977	1,755
Leases	1,904	2,067
Pensions	1,397	1,219
Postretirement benefits other than pensions	203	145
Rent expense	96	126
Reorganization items	28	30
Alternative minimum tax (AMT) credit carryforwards	0	118
Other	796	569
Total deferred tax assets	10,345	8,144
Valuation allowance	(24)	(24)
Net deferred tax assets	10,321	8,120
Deferred tax liabilities:
Accelerated depreciation and amortization	(4,992)	(5,153)
Leases	(1,809)	(1,968)
Other	(294)	(340)
Total deferred tax liabilities	(7,095)	(7,461)
Net deferred tax asset	$ 3,226	$ 659