OPERATING SEGMENT INFORMATION (DETAILS) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Capacity purchase arrangements	100.00%
Operating revenues
Passenger, Mainline	$ 901us-gaap_PassengerRevenueMainline	$ 854us-gaap_PassengerRevenueMainline
Passenger, Regional	186us-gaap_PassengerRevenueRegional	186us-gaap_PassengerRevenueRegional
Total passenger revenue	1,087us-gaap_PassengerRevenue	1,040us-gaap_PassengerRevenue
Segment Reporting Information, Intersegment Revenue	0us-gaap_Revenues	0us-gaap_Revenues
Freight and mail	23us-gaap_CargoAndFreightRevenue	24us-gaap_CargoAndFreightRevenue
Other - net revenue	159alk_OtherNetandSpecialRevenue	158alk_OtherNetandSpecialRevenue
Total Operating Revenues	1,269us-gaap_SalesRevenueNet	1,222us-gaap_SalesRevenueNet
Operating expenses
Operating expenses, excluding fuel	796alk_OperatingExpensesExcludingFuel	723alk_OperatingExpensesExcludingFuel
Economic fuel	235us-gaap_FuelCosts	358us-gaap_FuelCosts
Total Operating Expenses	1,031us-gaap_OperatingExpenses	1,081us-gaap_OperatingExpenses
Nonoperating Income (Expense)
Interest income	5us-gaap_InvestmentIncomeInterest	5us-gaap_InvestmentIncomeInterest
Interest expense	(11)us-gaap_InterestExpense	(12)us-gaap_InterestExpense
Other	8alk_OtherNonoperatingIncomeExpenseOther	18alk_OtherNonoperatingIncomeExpenseOther
Nonoperating Income (Expense) Total	2us-gaap_NonoperatingIncomeExpense	11us-gaap_NonoperatingIncomeExpense
Income (loss) before income tax	240	152
Air Group Adjusted [Member]
Operating revenues
Passenger, Mainline	901	854
Passenger, Regional	186	186
Total passenger revenue	1,087	1,040
Segment Reporting Information, Intersegment Revenue	0	0
Freight and mail	23	24
Other - net revenue	159	158
Total Operating Revenues	1,269	1,222
Operating expenses
Operating expenses, excluding fuel	796	723
Economic fuel	235	366
Total Operating Expenses	1,031	1,089
Nonoperating Income (Expense)
Interest income	5	5
Interest expense	(11)	(12)
Other	8	18
Nonoperating Income (Expense) Total	2	11
Income (loss) before income tax	240	144
Alaska Mainline [Member]
Operating revenues
Passenger, Mainline	901	854
Passenger, Regional	0	0
Total passenger revenue	901	854
Segment Reporting Information, Intersegment Revenue	0	0
Freight and mail	22	23
Other - net revenue	142	140
Total Operating Revenues	1,065	1,017
Operating expenses
Operating expenses, excluding fuel	639	576
Economic fuel	203	318
Total Operating Expenses	842	894
Nonoperating Income (Expense)
Interest income	5	5
Interest expense	(7)	(8)
Other	7	18
Nonoperating Income (Expense) Total	5	15
Income (loss) before income tax	228	138
Alaska Regional [Member]
Operating revenues
Passenger, Mainline	0	0
Passenger, Regional	186	186
Total passenger revenue	186	186
Segment Reporting Information, Intersegment Revenue	0	0
Freight and mail	1	1
Other - net revenue	16	17
Total Operating Revenues	203	204
Operating expenses
Operating expenses, excluding fuel	164	151
Economic fuel	32	48
Total Operating Expenses	196	199
Nonoperating Income (Expense)
Interest income	0	0
Interest expense	0	0
Other	0	(1)
Nonoperating Income (Expense) Total	0	(1)
Income (loss) before income tax	7	4
Horizon [Member]
Operating revenues
Passenger, Mainline	0	0
Passenger, Regional	0	0
Total passenger revenue	0	0
Segment Reporting Information, Intersegment Revenue	99	91
Freight and mail	0	0
Other - net revenue	1	1
Total Operating Revenues	100	92
Operating expenses
Operating expenses, excluding fuel	91	86
Economic fuel	0	0
Total Operating Expenses	91	86
Nonoperating Income (Expense)
Interest income	0	0
Interest expense	(4)	(4)
Other	1	1
Nonoperating Income (Expense) Total	(3)	(3)
Income (loss) before income tax	6	3
Intersegment Elimination [Member]
Operating revenues
Passenger, Mainline	0	0
Passenger, Regional	0	0
Total passenger revenue	0	0
Segment Reporting Information, Intersegment Revenue	(99)	(91)
Freight and mail	0	0
Other - net revenue	0	0
Total Operating Revenues	(99)	(91)
Operating expenses
Operating expenses, excluding fuel	(98)	(90)
Economic fuel	0	0
Total Operating Expenses	(98)	(90)
Nonoperating Income (Expense)
Interest income	0	0
Interest expense	0	0
Other	0	0
Nonoperating Income (Expense) Total	0	0
Income (loss) before income tax	(1)	(1)
Special Revenue and Charges [Member]
Operating revenues
Passenger, Mainline	0	0
Passenger, Regional	0	0
Total passenger revenue	0	0
Segment Reporting Information, Intersegment Revenue	0	0
Freight and mail	0	0
Other - net revenue	0	0
Total Operating Revenues	0	0
Operating expenses
Operating expenses, excluding fuel	0	0
Economic fuel	0	(8)
Total Operating Expenses	0	(8)
Nonoperating Income (Expense)
Interest income	0	0
Interest expense	0	0
Other	0	0
Nonoperating Income (Expense) Total	0	0
Income (loss) before income tax	$ 0	$ 8

Airline, Capacity Purchase Arrangements, Percent

No definition available.

Name:	alk_AirlineCapacityPurchaseArrangementsPercent
Namespace Prefix:	alk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Operating Expenses, Excluding Fuel

+ References

No definition available.

+ Details

Name:	alk_OperatingExpensesExcludingFuel
Namespace Prefix:	alk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Other Net and Special Revenue

+ References

No definition available.

+ Details

Name:	alk_OtherNetandSpecialRevenue
Namespace Prefix:	alk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Other Nonoperating Income Expense Other

+ References

No definition available.

+ Details

Name:	alk_OtherNonoperatingIncomeExpenseOther
Namespace Prefix:	alk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Revenue from transporting cargo and freight between locations.

+ References

+ Details

Name:	us-gaap_CargoAndFreightRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period.

+ References

+ Details

Name:	us-gaap_FuelCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h)(1)(i))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of the cost of borrowed funds accounted for as interest expense.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.9)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 9

-Article 9

+ Details

Name:	us-gaap_InterestExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.7(b))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

Name:	us-gaap_InvestmentIncomeInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.7)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Article 5

+ Details

Name:	us-gaap_NonoperatingIncomeExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_NonoperatingIncomeExpenseAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

+ References

No definition available.

+ Details

Name:	us-gaap_OperatingExpenses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_OperatingExpensesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

A transportation (plane, train, ship) carrier's fare revenue recognized in the period from carrying passengers between destinations.

+ References

+ Details

Name:	us-gaap_PassengerRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of a transportation carrier's mainline fare revenue recognized in the period from carrying passengers between destinations.

+ References

No definition available.

+ Details

Name:	us-gaap_PassengerRevenueMainline
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of a transportation carrier's regional affiliates' fare revenue recognized in the period from carrying passengers between destinations.

+ References

No definition available.

+ Details

Name:	us-gaap_PassengerRevenueRegional
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

Name:	us-gaap_Revenues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_RevenuesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

Name:	us-gaap_SalesRevenueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=alk_AirGroupAdjustedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=alk_AlaskaMainlineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=alk_AlaskaRegionalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=alk_HorizonMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=alk_SpecialRevenueandChargesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=us-gaap_IntersegmentEliminationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: