OPERATING SEGMENT INFORMATION, ASSETS (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Total assets	$ 5,644		$ 5,505
Alaska Airlines [Member]
Total assets	5,346	[1]	5,177	[1]
Horizon [Member]
Total assets	825		823
Parent [Member]
Total assets	1,891		1,832
Intersegment Elimination [Member]
Total assets	$ (2,418)		$ (2,327)

[1] There are no assets associated with purchased capacity flying at Alaska.