XML 162 R83.htm IDEA: XBRL DOCUMENT
v3.25.0.1

EMPLOYEE RETIREMENT PLANS - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items] |  |  |
Company contributions to all defined contribution plans expensed | $ 843 | $ 941 | $ 793
Defined benefit plan, eligible wages (as percent) | 1.00% |  |
Defined benefit plan, distribution of single Life annuity for joint and survivor (as percent) | 50.00% |  |
Maximum age after retirement that employees may use accrued unused sick time to pay for medical and dental premiums | 65 years |  |
Actuarial gains | $ 36 |  |
Postretirement Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Actuarial gains | $ 35 | $ (11) |
Defined Benefit Plan, Equity Securities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, target allocation (as percent) | 40.00% |  |
Fixed Income Funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, target allocation (as percent) | 60.00% |  |

X
- Definition Defined Benefit Plan, Distribution Of Single Life Annuity For Joint And Survivor, Percentage + References No definition available. + Details
Name: | luv_DefinedBenefitPlanDistributionOfSingleLifeAnnuityForJointAndSurvivorPercentage
Namespace Prefix: | luv_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan, Eligible Wages, Percentage + References No definition available. + Details
Name: | luv_DefinedBenefitPlanEligibleWagesPercentage
Namespace Prefix: | luv_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum age after retirement that employees may use accrued unused sick time to pay for medical and dental premiums if they meet minimum levels of service and age requirements set forth by the company or as specified in collective bargaining agreements. + References No definition available. + Details
Name: | luv_DefinedContributionPensionPlansMaximumAgeRequirementForPayingMedicalAndDentalPremiumsWithAccruedUnusedSickTime
Namespace Prefix: | luv_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a)(4) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanActuarialGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480482/715-20-55-17 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of cost for defined contribution plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 70 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480794/715-70-50-1 + Details
Name: | us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_DefinedBenefitPlanEquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_FixedIncomeFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |