OPERATING SEGMENT INFORMATION (Details) $ in Millions		12 Months Ended
		Dec. 31, 2015 USD ($) airline segment	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Segment Reporting Information [Line Items]
Number of operating airlines | airline		2
Number of operating segments | segment		3
Operating revenues
Passenger, Mainline		$ 3,939	$ 3,774	$ 3,490
Passenger, Regional		854	805	777
Total passenger revenue		4,793	4,579	4,267
CPA revenues		0	0	0
Freight and mail		108	114	113
Other Net and Special Revenue		697	675	776
Total Operating Revenues		5,598	5,368	5,156
Operating expenses
Operating expenses, excluding fuel		3,346	2,988	2,851
Economic fuel		954	1,418	1,467
Total Operating Expenses		4,300	4,406	4,318
Nonoperating income (expense)
Interest income		21	21	18
Interest expense		(42)	(48)	(56)
Other		35	40	16
Nonoperating Income (Expense) Total		14	13	(22)
Income (loss) before income tax		1,312	975	816
Income before income tax			975	816
Depreciation		320	294	270
Capital expenditures		831	694	566
Total assets		6,533	6,064
Air Group Adjusted [Member]
Operating revenues
Passenger, Mainline	[1]	3,939	3,774	3,490
Passenger, Regional	[1]	854	805	777
Total passenger revenue	[1]	4,793	4,579	4,267
CPA revenues	[1]	0	0	0
Freight and mail	[1]	108	114	113
Other Net and Special Revenue	[1]	697	675	584
Total Operating Revenues	[1]	5,598	5,368	4,964
Operating expenses
Operating expenses, excluding fuel	[1]	3,314	3,018	2,851
Economic fuel	[1]	954	1,441	1,475
Total Operating Expenses	[1]	4,268	4,459	4,326
Nonoperating income (expense)
Interest income	[1]	21	21	18
Interest expense	[1]	(42)	(48)	(56)
Other	[1]	35	40	16
Nonoperating Income (Expense) Total	[1]	14	13	(22)
Income (loss) before income tax	[1]	1,344	922	616
Alaska Airlines [Member]
Nonoperating income (expense)
Depreciation	[2]	268	243	223
Capital expenditures	[2]	821	659	494
Total assets	[2]	8,129	6,665
Alaska Mainline [Member]
Operating revenues
Passenger, Mainline		3,939	3,774	3,490
Passenger, Regional		0	0	0
Total passenger revenue		3,939	3,774	3,490
CPA revenues		0	0	0
Freight and mail		103	109	109
Other Net and Special Revenue		621	592	513
Total Operating Revenues		4,663	4,475	4,112
Operating expenses
Operating expenses, excluding fuel		2,653	2,417	2,293
Economic fuel		823	1,251	1,294
Total Operating Expenses		3,476	3,668	3,587
Nonoperating income (expense)
Interest income		19	20	18
Interest expense		(28)	(32)	(38)
Other		28	39	25
Nonoperating Income (Expense) Total		19	27	5
Income (loss) before income tax		1,206	834	530
Alaska Regional [Member]
Operating revenues
Passenger, Mainline		0	0	0
Passenger, Regional		854	805	777
Total passenger revenue		854	805	777
CPA revenues		0	0	0
Freight and mail		5	5	4
Other Net and Special Revenue		72	78	66
Total Operating Revenues		931	888	847
Operating expenses
Operating expenses, excluding fuel		695	623	585
Economic fuel		131	190	181
Total Operating Expenses		826	813	766
Nonoperating income (expense)
Interest income		0	0	0
Interest expense		0	0	0
Other		0	(1)	(12)
Nonoperating Income (Expense) Total		0	(1)	(12)
Income (loss) before income tax		105	74	69
Horizon [Member]
Operating revenues
Passenger, Mainline		0	0	0
Passenger, Regional		0	0	0
Total passenger revenue		0	0	0
CPA revenues		408	371	368
Freight and mail		0	0	0
Other Net and Special Revenue		4	5	5
Total Operating Revenues		412	376	373
Operating expenses
Operating expenses, excluding fuel		375	349	341
Economic fuel		0	0	0
Total Operating Expenses		375	349	341
Nonoperating income (expense)
Interest income		0	0	0
Interest expense		(10)	(12)	(14)
Other		1	2	2
Nonoperating Income (Expense) Total		(9)	(10)	(12)
Income (loss) before income tax		28	17	20
Depreciation		52	51	47
Capital expenditures		10	35	72
Total assets		718	809
Parent [Member]
Nonoperating income (expense)
Depreciation		0	0	0
Total assets		4,734	3,551
Intersegment Eliminations
Operating revenues
Passenger, Mainline		0	0	0
Passenger, Regional		0	0	0
Total passenger revenue		0	0	0
CPA revenues		(408)	$ (371)	(368)
Freight and mail		0		0
Other Net and Special Revenue		0		0
Total Operating Revenues		(408)	$ (371)	(368)
Operating expenses
Operating expenses, excluding fuel		(409)	(371)	(368)
Economic fuel		0	0	0
Total Operating Expenses		(409)	(371)	(368)
Nonoperating income (expense)
Interest income		2	1	0
Interest expense		(4)	(4)	(4)
Other		6	0	1
Nonoperating Income (Expense) Total		4	(3)	(3)
Income (loss) before income tax		5	(3)	(3)
Total assets		(7,048)	(4,961)
Special Charges [Member]
Operating revenues
Passenger, Mainline	[3]	0	0	0
Passenger, Regional	[3]	0	0	0
Total passenger revenue	[3]	0	0	0
CPA revenues	[3]	0	0	0
Freight and mail	[3]	0	0	0
Other Net and Special Revenue	[3]	0	0	192
Total Operating Revenues	[3]	0	0	192
Operating expenses
Operating expenses, excluding fuel	[3]	32	(30)	0
Economic fuel	[3]	0	(23)	(8)
Total Operating Expenses	[3]	32	(53)	(8)
Nonoperating income (expense)
Interest income	[3]	0	0	0
Interest expense	[3]	0	0	0
Other	[3]	0	0	0
Nonoperating Income (Expense) Total	[3]	0	0	0
Income (loss) before income tax	[3]	$ (32)	$ 53	$ 200

[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 income and charges.

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

[3] Includes accounting adjustments related to mark-to-market fuel-hedge accounting charges (all years), pension settlement charge (2015), litigation-related matter (2015), non-cash curtailment gain (2014), a gain related to a legal matter (2014), and Special mileage plan revenue (2013).