Finance leased asset, Number of units

No definition available.

Name:	alk_FinanceLeasedAssetNumberOfUnits
Namespace Prefix:	alk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of cash outflow for principal payment on finance lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
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-Subparagraph (g)(1)
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479041/842-20-45-5

+ Details

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

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147478964/842-20-50-3

+ Details

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

- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147478964/842-20-50-3

+ Details

Name:	us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount lessor expects from underlying asset following end of operating lease term for lease that has not yet commenced.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479773/842-30-50-3

+ Details

Name:	us-gaap_LessorOperatingLeaseLeaseNotYetCommencedAssumptionAndJudgmentValueOfUnderlyingAssetAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
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-Subparagraph (c)
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-URI https://asc.fasb.org//1943274/2147478964/842-20-50-4

+ Details

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

- Definition

The number of units (items of property) under operating lease arrangements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479773/842-30-50-13

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details

Name:	us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNumberOfUnits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of increase in right-of-use asset obtained in exchange for operating lease liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479589/842-20-55-53

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org//1943274/2147478964/842-20-50-4

+ Details

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

- Definition

Amount of sublease income excluding finance and operating lease expense.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 53
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-URI https://asc.fasb.org//1943274/2147479589/842-20-55-53

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+ Details

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

- Definition

Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 53
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479589/842-20-55-53

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+ Details

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

- Details

Name:	srt_AircraftTypeAxis=alk_E175Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_AircraftTypeAxis=srt_B737MaxMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_AircraftTypeAxis=alk_B737800FMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis=us-gaap_PropertySubjectToOperatingLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_AircraftTypeAxis=srt_B737Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_AircraftTypeAxis=alk_A320NonopMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis=alk_AirportFacilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis=alk_AircraftMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis=alk_CorporaterealestateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

LEASES - NARRATIVE (Details) $ in Millions	12 Months Ended
LEASES - NARRATIVE (Details) $ in Millions	Dec. 31, 2023 USD ($) aircraft	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Lessee, Lease, Description [Line Items]
Sublease Income	$ 15	$ 15	$ 16
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	178	461	273
Operating Lease, Payments	348
Finance Lease, Principal Payments	$ 211
Finance leased asset, Number of units \| aircraft	1
Lessor, Operating Lease, Lease Not yet Commenced, Assumption and Judgment, Value of Underlying Asset, Amount	$ 47
E175 [Member] \| Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	11 years
B737 MAX [Member] \| Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	12 years
B-737-800F \| Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	11 years
Property Subject to Operating Lease [Member] \| E175 [Member]
Lessee, Lease, Description [Line Items]
Operating leases, number of leased assets (in aircraft) \| aircraft	42
Property Subject to Operating Lease [Member] \| B737-800
Lessee, Lease, Description [Line Items]
Operating leases, number of leased assets (in aircraft) \| aircraft	10
Property Subject to Operating Lease [Member] \| B737 MAX [Member]
Lessee, Lease, Description [Line Items]
Operating leases, number of leased assets (in aircraft) \| aircraft	14
Property Subject to Operating Lease [Member] \| A320, nonop [Member]
Lessee, Lease, Description [Line Items]
Operating leases, number of leased assets (in aircraft) \| aircraft	16
Property Subject to Operating Lease [Member] \| B-737-800F
Lessee, Lease, Description [Line Items]
Operating leases, number of leased assets (in aircraft) \| aircraft	1
Airport Facilities [Member]
Lessee, Lease, Description [Line Items]
Variable Lease, Cost	$ 447	381	377
Aircraft Leases [Member]
Lessee, Lease, Description [Line Items]
Variable Lease, Cost	10	10	5
Corporate real estate [Member]
Lessee, Lease, Description [Line Items]
Variable Lease, Cost	$ 15	$ 27	$ 17