Leases - Components of Lease Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 2,027	$ 1,907
Finance lease cost:
Amortization of assets	79	78
Interest on lease liabilities	43	48
Variable lease cost	2,558	2,353
Total net lease cost	4,707	4,386
American Airlines, Inc. [Member]
Lessee, Lease, Description [Line Items]
Operating lease cost	2,012	1,889
Finance lease cost:
Amortization of assets	79	78
Interest on lease liabilities	43	48
Variable lease cost	2,542	2,353
Total net lease cost	$ 4,676	$ 4,368