OPERATING SEGMENT INFORMATION, ASSETS (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Total assets	$ 7,035	$ 6,530
Alaska Airlines [Member]
Total assets	9,101	8,127
Horizon [Member]
Total assets	729	717
Parent [Member]
Total assets	5,200	4,734
Intersegment Elimination [Member]
Total assets	$ (7,995)	$ (7,048)