OPERATING SEGMENT INFORMATION, ASSETS (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Total assets	$ 15,165	$ 14,186
Alaska Airlines [Member]
Total assets	20,468	19,733
Horizon [Member]
Total assets	1,320	1,157
Consolidating and Other [Member]
Total assets	$ (6,623)	$ (6,704)