Employee Benefit Plans - Schedule of One Percentage Point Change in Assumed Health Care Cost Trend Rates (Detail) $ in Millions |
12 Months Ended |
---|---|
Dec. 31, 2017
USD ($)
| |
Defined Benefit Plan Disclosure [Line Items] | |
Increase (decrease) on 2017 service and interest cost, 1% Increase | $ 2 |
Increase (decrease) on benefit obligation as of December 31, 2017, 1% Increase | 54 |
Increase (decrease) on 2017 service and interest cost, 1% Decrease | (2) |
Increase(decrease) on benefits obligation as of December 31, 2017, 1% Decrease | (51) |
American Airlines, Inc. [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Increase (decrease) on 2017 service and interest cost, 1% Increase | 2 |
Increase (decrease) on benefit obligation as of December 31, 2017, 1% Increase | 54 |
Increase (decrease) on 2017 service and interest cost, 1% Decrease | (2) |
Increase(decrease) on benefits obligation as of December 31, 2017, 1% Decrease | $ (51) |