Leases - Supplemental Cash Flow and Other Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 1,931
Operating cash flows from finance leases	48
Financing cash flows from finance leases	78
ROU assets obtained in exchange for lease liabilities:
Operating leases	1,292
Gain on sale leaseback transactions, net	59
American Airlines, Inc. [Member]
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	1,914
Operating cash flows from finance leases	48
Financing cash flows from finance leases	78
ROU assets obtained in exchange for lease liabilities:
Operating leases	1,258
Gain on sale leaseback transactions, net	$ 59