Basis of Presentation and Summary of Significant Accounting Policies - Components of Regional Expenses (Parenthetical) (Detail) - Regional Carrier [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Regional Expenses [Line Items]
Capacity purchase expenses related to aircraft deemed to be leased	$ 405	$ 492	$ 447
American Airlines, Inc. [Member]
Regional Expenses [Line Items]
Capacity purchase expenses related to aircraft deemed to be leased	$ 405	$ 492	$ 447