Employee Benefit Plans - Schedule of Changes in Fair Value of Plan Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period	$ 10,017	$ 9,707
Actual return on plan assets	1,797	915
Employer contributions	286	32
Settlements	(4)	(2)
Benefit payments	(726)	(635)
Other	25	0
Fair value of plan assets at end of period	11,395	10,017
Funded status at end of period	(6,880)	(7,221)
Supplemental contributions by employer	261
Minimum required cash contribution	25
Retiree Medical And Other Postretirement Benefits [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period	266	253
Actual return on plan assets	37	22
Employer contributions	72	83
Settlements	0	0
Benefit payments	(80)	(92)
Other	0	0
Fair value of plan assets at end of period	295	266
Funded status at end of period	(716)	(725)
American Airlines, Inc. [Member] | Pension Benefits [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period	9,968	9,660
Actual return on plan assets	1,788	911
Employer contributions	286	32
Settlements	(4)	(2)
Benefit payments	(723)	(633)
Other	25	0
Fair value of plan assets at end of period	11,340	9,968
Funded status at end of period	6,835	7,180
Supplemental contributions by employer	261
Minimum required cash contribution	25
American Airlines, Inc. [Member] | Retiree Medical And Other Postretirement Benefits [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period	266	253
Actual return on plan assets	37	22
Employer contributions	72	83
Settlements	0	0
Benefit payments	(80)	(92)
Other	0	0
Fair value of plan assets at end of period	295	266
Funded status at end of period	$ 715	$ 724