Basis of Presentation and Summary of Significant Accounting Policies - Regional Expenses (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Regional Expenses [Line Items]
Aircraft fuel and related taxes	$ 6,128	$ 5,071	$ 6,226
Salaries, wages and benefits	11,816	10,890	9,524
Maintenance, materials and repairs	1,959	1,834	1,889
Other rent and landing fees	1,806	1,772	1,731
Aircraft rent	1,197	1,203	1,250
Selling expenses	1,477	1,323	1,394
Depreciation and amortization	1,702	1,525	1,364
Other	4,806	4,525	4,374
Total regional expenses	6,546	6,044	5,983
Regional Carrier [Member]
Regional Expenses [Line Items]
Aircraft fuel and related taxes	1,382	1,109	1,230
Salaries, wages and benefits	1,452	1,333	1,187
Capacity purchases from third-party regional carriers	1,581	1,538	1,651
Maintenance, materials and repairs	281	345	323
Other rent and landing fees	625	564	504
Aircraft rent	35	36	34
Selling expenses	361	347	333
Depreciation and amortization	315	301	252
Special items, net	22	14	29
Other	492	457	440
Total regional expenses	6,546	6,044	5,983
Capacity purchase expenses related to aircraft deemed to be leased	437	405	492
American Airlines, Inc. [Member]
Regional Expenses [Line Items]
Aircraft fuel and related taxes	6,128	5,071	6,226
Salaries, wages and benefits	11,804	10,881	9,514
Maintenance, materials and repairs	1,959	1,834	1,889
Other rent and landing fees	1,806	1,772	1,731
Aircraft rent	1,197	1,203	1,250
Selling expenses	1,477	1,323	1,394
Depreciation and amortization	1,702	1,525	1,364
Other	4,806	4,532	4,378
Total regional expenses	6,572	6,009	5,952
American Airlines, Inc. [Member] | Regional Carrier [Member]
Regional Expenses [Line Items]
Aircraft fuel and related taxes	1,382	1,109	1,230
Salaries, wages and benefits	356	327	276
Capacity purchases from third-party regional carriers	3,283	3,186	3,137
Maintenance, materials and repairs	7	4	4
Other rent and landing fees	602	487	434
Aircraft rent	27	28	28
Selling expenses	361	347	333
Depreciation and amortization	262	237	197
Special items, net	3	13	18
Other	289	271	295
Total regional expenses	6,572	6,009	5,952
Capacity purchase expenses related to aircraft deemed to be leased	$ 437	$ 405	$ 492