Name:	luv_CashCollateralPercentOfFairValueFuelDerivativesContracts
Namespace Prefix:	luv_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

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

No definition available.

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

Investment Grade Rating Fair Value Of Fuel Derivative Level In Which Cash Is Received

No definition available.

Name:	luv_InvestmentGradeRatingFairValueOfFuelDerivativeLevelInWhichCashIsReceived
Namespace Prefix:	luv_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Investment Grade Rating Fair Value Of Fuel Derivative Levels In Which Cash Is Provided Threshold 1

No definition available.

Name:	luv_InvestmentGradeRatingFairValueOfFuelDerivativeLevelsInWhichCashIsProvidedThreshold1
Namespace Prefix:	luv_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Letter Of Credit Percent Of Collateral

No definition available.

Name:	luv_LetterOfCreditPercentOfCollateral
Namespace Prefix:	luv_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

Letters of Credit Collateral Pledged Aggregate Fair Value

No definition available.

Name:	luv_LettersofCreditCollateralPledgedAggregateFairValue
Namespace Prefix:	luv_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Maximum sum of derivatives of a counterparty to be included in Other and no risk of the Company posting collateral.

No definition available.

Name:	luv_MaximumSumOfDerivativesOfCounterpartyToBeIncludedInOther
Namespace Prefix:	luv_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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

No definition available.

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

Non-Investment Grade Rating Fair Value Of Fuel Derivative Level In Which Cash Is Received

No definition available.

Name:	luv_NonInvestmentGradeRatingFairValueOfFuelDerivativeLevelInWhichCashIsReceived
Namespace Prefix:	luv_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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.

No definition available.

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

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5624258-113959

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

Fair value, after offset of derivative liability, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226006-175313

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=125515794&loc=d3e41678-113959

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

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CommodityContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CounterpartyNameAxis=luv_CounterpartyAlphaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

Name:	srt_CounterpartyNameAxis=luv_CounterpartyBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CounterpartyNameAxis=luv_CounterpartyCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CounterpartyNameAxis=luv_CounterpartyDMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CounterpartyNameAxis=luv_CounterpartyEMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CounterpartyNameAxis=luv_CounterpartyFMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CounterpartyNameAxis=luv_CounterpartyGMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: