Deferred Compensation Arrangement with Individual, Individual Age And Term Of Service

No definition available.

Name:	luv_DeferredCompensationArrangementWithIndividualIndividualAgeAndTermOfService
Namespace Prefix:	luv_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the discount off the market price for each purchase right under the employee stock purchase plan.

+ References

No definition available.

+ Details

Name:	luv_DiscountPercentageOffMarketValueForSharesAvailableUnderEmployeeStockPurchasePlan
Namespace Prefix:	luv_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

-- None. No documentation exists for this element. --

+ References

No definition available.

+ Details

Name:	luv_EmployeeStockPurchasePlanAbstract
Namespace Prefix:	luv_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the percentage of market price at which shares may be issued to employees participating in the employee stock purchase plan.

+ References

No definition available.

+ Details

Name:	luv_PercentageOfMarketValueForSharesAvailableUnderEmployeeStockPurchasePlan
Namespace Prefix:	luv_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of PBRSUs to be granted

+ References

No definition available.

+ Details

Name:	luv_PercentageofPBRSUstobegranted
Namespace Prefix:	luv_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Minimum Percentage

+ References

No definition available.

+ Details

Name:	luv_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsMinimumPercentage
Namespace Prefix:	luv_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Rights, Termination Period

+ References

No definition available.

+ Details

Name:	luv_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsTerminationPeriod
Namespace Prefix:	luv_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average price of non-option equity instruments granted.

+ References

No definition available.

+ Details

Name:	luv_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAveragePrice
Namespace Prefix:	luv_
Data Type:	dtr-types1:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the remaining balance of shares originally authorized for issue under the employee stock purchase plan.

+ References

No definition available.

+ Details

Name:	luv_StockAvailableForIssueNumberEmployeeStockPurchasePlan
Namespace Prefix:	luv_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479830/718-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

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

- Definition

Minimum period the individual is required to perform services to be fully vested under the deferred compensation arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 55
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482943/710-10-55-7

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 718
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-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualRequisiteServicePeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

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

- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Net number of non-option equity instruments granted to participants.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(1)
-SubTopic 10
-Topic 718
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of vesting of award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage
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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
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- Details

Name:	us-gaap_AwardDateAxis=luv_GrantYear2021Member
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- Details

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- Details

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- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
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- Details

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STOCK PLANS - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Employee service share based compensation aggregate disclosures [Abstract]
Share based compensation cost	$ 86	$ 84	$ 58
Total unrecognized compensation cost related to share-based compensation arrangements	$ 60
Weighted average period of time over which unrecognized compensation cost is to be recognized (in years)	1 year 8 months 12 days
Minimum employee service period (in years)	10 years
Age and number of years of service	65 years
The remaining number of RSU's or stock options that may be issued (in shares)	30,000,000
Employee stock purchase plan [Abstract]
The remaining balance of shares originally authorized for issue under the employee stock purchase plan (in shares)	17,000,000
The percentage of market value at which shares may be issued to participating employees (as a percent)	90.00%
The discount percentage off the market value for the employee stock purchase plan (in hundredths)	10.00%
Performance Shares
Employee service share based compensation aggregate disclosures [Abstract]
Termination period (in months)	12 months
Performance Shares \| Grant Year 2021
Employee service share based compensation aggregate disclosures [Abstract]
Vesting percentage (as a percent)	276.00%
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Minimum Percentage	50.00%
Performance Shares \| Grant Year 2022
Employee service share based compensation aggregate disclosures [Abstract]
Vesting percentage (as a percent)	100.00%
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Minimum Percentage	50.00%
Performance Shares \| Grant Year 2023
Employee service share based compensation aggregate disclosures [Abstract]
Vesting percentage (as a percent)	100.00%
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Minimum Percentage	50.00%
Performance Shares \| Minimum \| Grant Year 2021
Employee service share based compensation aggregate disclosures [Abstract]
Percentage of PBRSUs to be granted	10.00%
Performance Shares \| Minimum \| Grant Year 2022
Employee service share based compensation aggregate disclosures [Abstract]
Percentage of PBRSUs to be granted	0.00%
Performance Shares \| Minimum \| Grant Year 2023
Employee service share based compensation aggregate disclosures [Abstract]
Percentage of PBRSUs to be granted	0.00%
Performance Shares \| Maximum \| Grant Year 2021
Employee service share based compensation aggregate disclosures [Abstract]
Percentage of PBRSUs to be granted	300.00%
Performance Shares \| Maximum \| Grant Year 2022
Employee service share based compensation aggregate disclosures [Abstract]
Percentage of PBRSUs to be granted	300.00%
Performance Shares \| Maximum \| Grant Year 2023
Employee service share based compensation aggregate disclosures [Abstract]
Percentage of PBRSUs to be granted	200.00%
Restricted stock units
Employee service share based compensation aggregate disclosures [Abstract]
The remaining number of RSU's or stock options that may be issued (in shares)	13,000,000
Restricted stock units \| Grant Year 2022
Employee service share based compensation aggregate disclosures [Abstract]
Vesting periods for plans (in years)	3 years
Restricted stock units \| Grant Year 2023
Employee service share based compensation aggregate disclosures [Abstract]
Vesting periods for plans (in years)	3 years
Restricted stock units \| Share-Based Payment Arrangement, Tranche One
Employee service share based compensation aggregate disclosures [Abstract]
Vesting percentage (as a percent)	33.00%
Restricted stock units \| Share-Based Payment Arrangement, Tranche Two
Employee service share based compensation aggregate disclosures [Abstract]
Vesting percentage (as a percent)	33.00%
Restricted stock units \| Share-Based Payment Arrangement, Tranche Three
Employee service share based compensation aggregate disclosures [Abstract]
Vesting percentage (as a percent)	33.00%
Stock Compensation Plan - Board of Directors
Employee service share based compensation aggregate disclosures [Abstract]
Non-option equity instruments granted (in shares)	73,000	42,000	27,000
Weighted average price of non-option equity instruments granted (in USD per share)	$ 30.12	$ 44.23	$ 60.39