XML 108 R82.htm IDEA: XBRL DOCUMENT v3.8.0.1
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)