XML 75 R59.htm IDEA: XBRL DOCUMENT
v3.6.0.2

EMPLOYEE BENEFIT PLANS EMPLOYEE BENEFIT PLANS - ADDITIONAL INFORMATION (Details) - plan | 1 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2016 | Dec. 31, 2016
Business Acquisition [Line Items] |  |
Number of defined benefit plans |  | 4
Number of defined contribution plans |  | 5
Virgin America Inc. [Member] |  |
Business Acquisition [Line Items] |  |
Number of defined contribution plans | 6 |

X
- Definition Number of Defined Benefit Plans + References No definition available. + Details
Name: | alk_NumberofDefinedBenefitPlans
Namespace Prefix: | alk_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Defined Contribution Plans + References No definition available. + Details
Name: | alk_NumberofDefinedContributionPlans
Namespace Prefix: | alk_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=alk_VirginAmericaInc.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |