XML 79 R43.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

GENERAL AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - MAINTENANCE DEPOSITS (Details) - USD ($) $ in Millions | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Accounting Policies [Abstract] |  |
Aircraft Maintenance Deposits | $ 143 | $ 90

X
- Definition Aircraft Maintenance Deposits + References No definition available. + Details
Name: | alk_AircraftMaintenanceDeposits
Namespace Prefix: | alk_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration