Employee Benefit Plans - Schedule of Accumulated Benefit Obligations Exceeding Fair Value of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 18,327	$ 16,351
Accumulated benefit obligation	18,315	16,341
Fair value of plan assets	12,862	10,023
ABO less fair value of plan assets	5,453	6,318
Retiree Medical And Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	824	837
Fair value of plan assets	204	225
American Airlines, Inc. [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	18,215	16,254
Accumulated benefit obligation	18,204	16,246
Fair value of plan assets	12,794	9,971
ABO less fair value of plan assets	5,410	6,275
American Airlines, Inc. [Member] | Retiree Medical And Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	824	837
Fair value of plan assets	$ 204	$ 225