Commitments, Contingencies and Guarantees - Capacity Purchase Agreements (Detail) $ in Millions	Dec. 31, 2017 USD ($)
Airline Capacity Purchase Arrangements [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Capacity purchase agreement, percentage of reimbursement for certain variable costs	100.00%
2018	$ 1,457
2019	1,311
2020	1,063
2021	866
2022	699
2023 and Thereafter	2,073
Total	7,469
Obligations Related To Aircraft To Be Leased [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
2018	377
2019	355
2020	320
2021	282
2022	239
2023 and Thereafter	$ 699
American Airlines, Inc. [Member] | Airline Capacity Purchase Arrangements [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Capacity purchase agreement, percentage of reimbursement for certain variable costs	100.00%
2018	$ 1,457
2019	1,311
2020	1,063
2021	866
2022	699
2023 and Thereafter	2,073
Total	7,469
American Airlines, Inc. [Member] | Obligations Related To Aircraft To Be Leased [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
2018	377
2019	355
2020	320
2021	282
2022	239
2023 and Thereafter	$ 699