OPERATING SEGMENT INFORMATION, ASSETS (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Total assets	$ 8,699	$ 6,530
Alaska Airlines [Member]
Total assets	10,949	8,127
Horizon [Member]
Total assets	716	717
Parent [Member]
Total assets	5,479	4,734
Intersegment Elimination [Member]
Total assets	$ (8,445)	$ (7,048)