Supplemental Cash Flow Information - Cash Flow Information and Non-Cash Investing and Financing Activities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Non-cash investing and financing activities:
Equity investment	$ 120	$ 0	$ 0
Settlement of bankruptcy obligations	15	3	63
Capital lease obligations	0	0	5
Supplemental information:
Interest paid, net of amounts capitalized	1,040	964	873
Income taxes paid	20	16	20
American Airlines, Inc. [Member]
Non-cash investing and financing activities:
Equity investment	120	0	0
Settlement of bankruptcy obligations	15	3	63
Capital lease obligations	0	0	5
Supplemental information:
Interest paid, net of amounts capitalized	942	867	787
Income taxes paid	$ 18	$ 14	$ 19