Employee Benefit Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Retiree medical plan, plan amendment				$ 1,900,000,000
Amortization period of gains losses related to plan amendment				8 years
Unamortized actuarial gain	$ 631,000,000
Weighted-average assumptions used to determine net periodic benefit cost, expected return on plan assets	8.00%
Estimated future employer contributions for 2018	$ 42,000,000
Defined benefit plans estimated supplemental future employer contributions in next fiscal year	425,000,000
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Retiree medical plan, plan amendment	0	$ 0
The estimated actuarial gain (loss) and prior service credit (cost) that will be amortized into net periodic benefit cost over the next fiscal year	$ (172,000,000)
Weighted-average assumptions used to determine net periodic benefit cost, expected return on plan assets	8.00%	8.00%	8.00%
Retiree Medical And Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Retiree medical plan, plan amendment	$ 0	$ (7,000,000)
The estimated actuarial gain (loss) and prior service credit (cost) that will be amortized into net periodic benefit cost over the next fiscal year	$ 258,000,000
Weighted-average assumptions used to determine net periodic benefit cost, expected return on plan assets	8.00%	8.00%	8.00%
American Airlines, Inc. [Member]
Defined Benefit Plan Disclosure [Line Items]
Retiree medical plan, plan amendment				$ 1,900,000,000
Amortization period of gains losses related to plan amendment				8 years
Unamortized actuarial gain	$ 631,000,000
Estimated future employer contributions for 2018	39,000,000
Defined benefit plans estimated supplemental future employer contributions in next fiscal year	425,000,000
American Airlines, Inc. [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Retiree medical plan, plan amendment	0	$ 0
The estimated actuarial gain (loss) and prior service credit (cost) that will be amortized into net periodic benefit cost over the next fiscal year	$ (171,000,000)
Weighted-average assumptions used to determine net periodic benefit cost, expected return on plan assets	8.00%	8.00%	8.00%
American Airlines, Inc. [Member] | Retiree Medical And Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Retiree medical plan, plan amendment	$ 0	$ (7,000,000)
The estimated actuarial gain (loss) and prior service credit (cost) that will be amortized into net periodic benefit cost over the next fiscal year	$ 258,000,000
Weighted-average assumptions used to determine net periodic benefit cost, expected return on plan assets	8.00%	8.00%	8.00%