OPERATING SEGMENT INFORMATION (DETAILS) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Operating revenues
Passenger, Mainline	$ 3,284		$ 2,995		$ 2,595
Passenger, Regional	746		713		671
Total passenger revenue	4,030		3,708		3,266
CPA revenues	0		0		0
Freight and mail	111		109		106
Other - net	516		501		460
Total Operating Revenues	4,657		4,318		3,832
Operating expenses
Operating expenses, excluding fuel	2,666		2,571		2,460
Economic fuel	1,459		1,298		901
Total Operating Expenses	4,125		3,869		3,361
Nonoperating income (expense)
Interest income	19		22		29
Interest expense	(64)		(87)		(108)
Other	27		10		14
Nonoperating Income (Expense) Total	(18)		(55)		(65)
Income (loss) before income tax	514		394		406
Depreciation	264		247		230
Capital expenditures	518		387		185
Total assets	5,505		5,167
Air Group Adjusted [Member]
Operating revenues
Passenger, Mainline	3,284	[1]	2,995	[1]	2,595	[1]
Passenger, Regional	746	[1]	713	[1]	671	[1]
Total passenger revenue	4,030	[1]	3,708	[1]	3,266	[1]
CPA revenues	0		0		0
Freight and mail	111	[1]	109	[1]	106	[1]
Other - net	516	[1]	501	[1]	460	[1]
Total Operating Revenues	4,657	[1]	4,318	[1]	3,832	[1]
Operating expenses
Operating expenses, excluding fuel	2,666	[1]	2,532	[1]	2,447	[1]
Economic fuel	1,421	[1]	1,268	[1]	896	[1]
Total Operating Expenses	4,087	[1]	3,800	[1]	3,343	[1]
Nonoperating income (expense)
Interest income	19	[1]	22	[1]	29	[1]
Interest expense	(64)	[1]	(87)	[1]	(108)	[1]
Other	27	[1]	10	[1]	14	[1]
Nonoperating Income (Expense) Total	(18)	[1]	(55)	[1]	(65)	[1]
Income (loss) before income tax	552	[1]	463	[1]	424	[1]
Alaska Airlines [Member]
Nonoperating income (expense)
Depreciation	217	[2]	203	[2]	189	[2]
Capital expenditures	477	[2]	250	[2]	166	[2]
Total assets	5,177	[2]	4,775	[2]
Alaska Mainline [Member]
Operating revenues
Passenger, Mainline	3,284		2,995		2,595
Passenger, Regional	0		0		0
Total passenger revenue	3,284		2,995		2,595
CPA revenues	0		0		0
Freight and mail	107		105		102
Other - net	448		431		397
Total Operating Revenues	3,839		3,531		3,094
Operating expenses
Operating expenses, excluding fuel	2,131	[3]	2,015	[3]	1,917	[3]
Economic fuel	1,238	[4]	1,101	[4]	757	[4]
Total Operating Expenses	3,369		3,116		2,674
Nonoperating income (expense)
Interest income	19		24		35
Interest expense	(47)		(72)		(97)
Other	24		8		13
Nonoperating Income (Expense) Total	(4)		(40)		(49)
Income (loss) before income tax	466		375		371
Alaska Regional [Member]
Operating revenues
Passenger, Mainline	0		0		0
Passenger, Regional	746		713		308
Total passenger revenue	746		713		308
CPA revenues	0		0		0
Freight and mail	4		4		2
Other - net	61		62		23
Total Operating Revenues	811		779		333
Operating expenses
Operating expenses, excluding fuel	566	[3]	544	[3]	299	[3]
Economic fuel	183	[4]	167	[4]	0	[4]
Total Operating Expenses	749		711		299
Nonoperating income (expense)
Interest income	0		0		0
Interest expense	0		0		0
Other	0		0		0
Nonoperating Income (Expense) Total	0		0		0
Income (loss) before income tax	62		68		34
Horizon [Member]
Operating revenues
Passenger, Mainline	0		0		0
Passenger, Regional	0		0		363
Total passenger revenue	0		0		363
CPA revenues	369		369		274
Freight and mail	0		0		2
Other - net	7		8		40
Total Operating Revenues	376		377		679
Operating expenses
Operating expenses, excluding fuel	338	[3]	340	[3]	502	[3]
Economic fuel	0	[4]	0	[4]	139	[4]
Total Operating Expenses	338		340		641
Nonoperating income (expense)
Interest income	0		0		4
Interest expense	(16)		(17)		(20)
Other	2		2		0
Nonoperating Income (Expense) Total	(14)		(15)		(16)
Income (loss) before income tax	24		22		22
Depreciation	47		43		41
Capital expenditures	41		137		19
Total assets	823		847
Parent [Member]
Nonoperating income (expense)
Depreciation	0		1		0
Total assets	1,832		1,584
Intersegment Elimination [Member]
Operating revenues
Passenger, Mainline	0		0		0
Passenger, Regional	0		0		0
Total passenger revenue	0		0		0
CPA revenues	(369)		(369)		(274)
Freight and mail	0		0		0
Other - net	0		0		0
Total Operating Revenues	(369)		(369)		(274)
Operating expenses
Operating expenses, excluding fuel	(369)	[3]	(367)	[3]	(271)	[3]
Economic fuel	0	[4]	0	[4]	0	[4]
Total Operating Expenses	(369)		(367)		(271)
Nonoperating income (expense)
Interest income	0		(2)		(10)
Interest expense	(1)		2		9
Other	1				1
Nonoperating Income (Expense) Total	0		0		0
Income (loss) before income tax	0		(2)		(3)
Total assets	(2,327)		(2,039)
Special Charges [Member]
Operating revenues
Passenger, Mainline	0		0		0
Passenger, Regional	0		0		0
Total passenger revenue	0		0		0
CPA revenues	0		0		0
Freight and mail	0		0		0
Other - net	0		0		0
Total Operating Revenues	0		0		0
Operating expenses
Operating expenses, excluding fuel	0		39	[3]	13	[3]
Economic fuel	38	[4]	30	[4]	5	[4]
Total Operating Expenses	38		69		18
Nonoperating income (expense)
Interest income	0		0		0
Interest expense	0		0		0
Other	0		0		0
Nonoperating Income (Expense) Total	0		0		0
Income (loss) before income tax	$ (38)		$ (69)		$ (18)

[1] The adjusted column represents the financial information that is reviewed by management to assess performance of operations and determine capital allocations and does not include certain charges.

[2] There are no depreciation expenses, capital expenditures or assets associated with purchased capacity flying at Alaska Regional.

[3] Refer to the Fleet Transition and Restructuring Related Expenses note for a summary of special charges for each respective period.

[4] Represents adjustments to reflect the timing of gain or loss recognition resulting from mark-to-market fuel-hedge accounting.