Leases - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) aircraft	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Lessee, Lease, Description [Line Items]
Number of leased aircraft | aircraft	641
Operating lease cost	$ 1,957	$ 2,027	$ 1,907
Operating lease, impairment loss	109
Operating lease commitments that have not yet commenced	$ 1,700
Operating lease commitments that have not yet commenced, number of aircraft | aircraft	19
Operating lease commitments that have not yet commenced, lease term	10 years
Republic Holdings
Lessee, Lease, Description [Line Items]
Ownership interest	25.00%
Republic
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 172	236	226
American Airlines, Inc.
Lessee, Lease, Description [Line Items]
Number of leased aircraft | aircraft	641
Operating lease cost	$ 1,943	2,012	1,889
Operating lease, impairment loss	109
Operating lease commitments that have not yet commenced	$ 1,700
Operating lease commitments that have not yet commenced, number of aircraft | aircraft	19
Operating lease commitments that have not yet commenced, lease term	10 years
American Airlines, Inc. | Republic Holdings
Lessee, Lease, Description [Line Items]
Ownership interest	25.00%
American Airlines, Inc. | Republic
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 172	$ 236	$ 226
Minimum
Lessee, Lease, Description [Line Items]
Lease terms	1 year
Minimum | American Airlines, Inc.
Lessee, Lease, Description [Line Items]
Lease terms	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease terms	12 years
Maximum | American Airlines, Inc.
Lessee, Lease, Description [Line Items]
Lease terms	12 years