Income Taxes - Reconciliation of Income Tax Provision (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Line Items]
Statutory income tax provision		$ 396	$ 1,188	$ 1,453
State income tax provision, net of federal tax effect		44	59	56
Foreign income taxes, net of federal tax effect		23	7	6
Book expenses not deductible for tax purposes		12	33	35
Bankruptcy administration expenses		0	1	1
2017 Tax Act		0	823	0
Change in valuation allowance		(6)	(3)	7
Other, net		3	5	10
Total income tax provision		472	2,113	1,568
American Airlines, Inc. [Member]
Income Tax Disclosure [Line Items]
Statutory income tax provision		460	1,244	1,504
State income tax provision, net of federal tax effect		46	53	61
Foreign income taxes, net of federal tax effect		22	6	6
Book expenses not deductible for tax purposes		10	30	32
Bankruptcy administration expenses		0	1	1
2017 Tax Act		0	924	0
Change in valuation allowance	$ (22)	(6)	4	(1)
Other, net		2	8	4
Total income tax provision		$ 534	$ 2,270	$ 1,607