XML 80 R38.htm IDEA: XBRL DOCUMENT
v3.19.3

Financial Derivative Instruments - Fair Values of Fuel Derivatives Amounts Posted as Collateral (Details) - Fuel derivatives $ in Millions | Sep. 30, 2019 USD ($)
--- | ---
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | $ 114 |
Cash collateral held from (by) CP | 0 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty A |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 25 |
Cash collateral held from (by) CP | 0 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty B |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 18 |
Cash collateral held from (by) CP | 0 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty C |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 35 |
Cash collateral held from (by) CP | 0 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty D |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 12 |
Cash collateral held from (by) CP | 0 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty E |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 9 |
Cash collateral held from (by) CP | 0 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty F |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 7 |
Cash collateral held from (by) CP | 0 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty Other |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 8 | [1]
Cash collateral held from (by) CP | 0 | [1]
Aircraft collateral pledged to CP | 0 | [1]
Letters of credit (LC) | 0 | [1]
Minimum | Counterparty A |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (200) | [2]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (50) |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (600) |
Fair value of fuel derivative level at which cash is received from CP | 50 | [3]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (200) | [4]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | 0 |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (600) |
Fair value of fuel derivative level at which cash is received from CP |  | [5]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (200) |
Minimum | Counterparty B |  |
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (50) |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 |  |
Fair value of fuel derivative level at which cash is received from CP | 150 | [3]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 |  | [5]
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 |  |
Fair value of fuel derivative level at which cash is received from CP |  | [5]
Minimum | Counterparty C |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (150) | [6]
Fair Value Of Fuel Derivative Levels In Which Letters Of Credit May Be Substituted For Cash Threshold 1 | (75) | [6]
Option to substitute LC for cash Threshold 2 | (550) | [6]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (75) | [3]
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (550) | [3]
Fair value of fuel derivative level at which cash is received from CP | 250 | [3]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (150) | [6]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | 0 |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (550) |
Fair value of fuel derivative level at which cash is received from CP |  | [5]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (150) |
Minimum | Counterparty D |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (150) | [6]
Fair Value Of Fuel Derivative Levels In Which Letters Of Credit May Be Substituted For Cash Threshold 1 | (125) | [7]
Option to substitute LC for cash Threshold 2 | (550) | [7]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (125) | [3]
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (550) | [3]
Fair value of fuel derivative level at which cash is received from CP | 125 | [3]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (150) | [6]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | 0 |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (550) |
Fair value of fuel derivative level at which cash is received from CP |  | [5]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (150) |
Minimum | Counterparty E |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Fair Value Of Fuel Derivative Levels In Which Letters Of Credit May Be Substituted For Cash Threshold 1 |  | [7]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (40) |
Fair value of fuel derivative level at which cash is received from CP | 100 | [3]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 |  | [5]
Fair value of fuel derivative level at which cash is received from CP |  | [5]
Minimum | Counterparty F |  |
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (70) | [3]
Fair value of fuel derivative level at which cash is received from CP | 70 | [3]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 |  | [5]
Fair value of fuel derivative level at which cash is received from CP |  | [5]
Maximum | Counterparty A |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (600) | [2]
Fair Value Of Fuel Derivative Levels In Which Letters Of Credit May Be Substituted For Cash Threshold 1 |  |
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (200) |
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (600) | [4]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (200) |
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (600) |
Maximum | Counterparty C |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (550) | [6]
Fair Value Of Fuel Derivative Levels In Which Letters Of Credit May Be Substituted For Cash Threshold 1 | (150) | [6]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (150) | [3]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (550) | [6]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (150) |
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (550) |
Maximum | Counterparty D |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (550) | [6]
Fair Value Of Fuel Derivative Levels In Which Letters Of Credit May Be Substituted For Cash Threshold 1 | (150) | [7]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (150) | [3]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (550) | [6]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (150) |
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | $ (550) |
[1] | Individual counterparties with fair value of fuel derivatives < $7 million.
[2] | The Company has the option of providing letters of credit in addition to aircraft collateral if the appraised value of the aircraft does not meet the collateral requirements.
[3] | Thresholds may vary based on changes in credit ratings within investment grade.
[4] | The Company has the option of providing cash or pledging aircraft as collateral.
[5] | Cash collateral is provided at 100 percent of fair value of fuel derivative contracts.
[6] | The Company has the option of providing cash, letters of credit, or pledging aircraft as collateral.
[7] | The Company has the option to substitute letters of credit for 100 percent of cash collateral requirement.

X
- Definition The aggregate fair value of assets (aircraft) pledged, at the end of the reporting period, as collateral for outstanding derivative instruments with credit-risk-related contingent features. + References No definition available. + Details
Name: | luv_AircraftCollateralPledgedAggregateFairValue
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair Value Of Fuel Derivative Levels In Which Letters Of Credit May Be Substituted For Aircraft + References No definition available. + Details
Name: | luv_FairValueOfFuelDerivativeLevelsInWhichLettersOfCreditMayBeSubstitutedForAircraft
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair Value Of Fuel Derivative Levels In Which Letters Of Credit May Be Substituted For Cash Threshold 1 + References No definition available. + Details
Name: | luv_FairValueOfFuelDerivativeLevelsInWhichLettersOfCreditMayBeSubstitutedForCashThreshold1
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair Value Of Fuel Derivative Levels In Which Letters Of Credit May Be Substituted For Cash Threshold 2 + References No definition available. + Details
Name: | luv_FairValueOfFuelDerivativeLevelsInWhichLettersOfCreditMayBeSubstitutedForCashThreshold2
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition -- None. No documentation exists for this element. -- + References No definition available. + Details
Name: | luv_InvestmentGradeCreditRatingAbstract
Namespace Prefix: | luv_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Investment Grade Rating Fair Value Of Fuel Derivative Level In Which Cash Is Received + References No definition available. + Details
Name: | luv_InvestmentGradeRatingFairValueOfFuelDerivativeLevelInWhichCashIsReceived
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Investment Grade Rating Fair Value Of Fuel Derivative Levels In Which Aircraft Or Cash Collateral Is Pledged + References No definition available. + Details
Name: | luv_InvestmentGradeRatingFairValueOfFuelDerivativeLevelsInWhichAircraftOrCashCollateralIsPledged
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Investment Grade Rating Fair Value Of Fuel Derivative Levels In Which Cash Is Provided Threshold 1 + References No definition available. + Details
Name: | luv_InvestmentGradeRatingFairValueOfFuelDerivativeLevelsInWhichCashIsProvidedThreshold1
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Investment Grade Rating Fair Value Of Fuel Derivative Levels In Which Cash Is Provided Threshold 2 + References No definition available. + Details
Name: | luv_InvestmentGradeRatingFairValueOfFuelDerivativeLevelsInWhichCashIsProvidedThreshold2
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Letters of Credit Collateral Pledged Aggregate Fair Value + References No definition available. + Details
Name: | luv_LettersofCreditCollateralPledgedAggregateFairValue
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition -- None. No documentation exists for this element. -- + References No definition available. + Details
Name: | luv_NonInvestmentGradeCreditRatingAbstract
Namespace Prefix: | luv_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Non Investment Grade Rating Fair Value Of Fuel Derivative Level In Which Cash Is Provided Threshold 1 + References No definition available. + Details
Name: | luv_NonInvestmentGradeRatingFairValueOfFuelDerivativeLevelInWhichCashIsProvidedThreshold1
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Non Investment Grade Rating Fair Value Of Fuel Derivative Level In Which Cash Is Provided Threshold 2 + References No definition available. + Details
Name: | luv_NonInvestmentGradeRatingFairValueOfFuelDerivativeLevelInWhichCashIsProvidedThreshold2
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Non-Investment Grade Rating Fair Value Of Fuel Derivative Level In Which Cash Is Received + References No definition available. + Details
Name: | luv_NonInvestmentGradeRatingFairValueOfFuelDerivativeLevelInWhichCashIsReceived
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Non Investment Grade Rating Fair Value Of Fuel Derivative Levels at Which Aircraft Or Cash Collateral Is Pledged + References No definition available. + Details
Name: | luv_NonInvestmentGradeRatingFairValueOfFuelDerivativeLevelsatWhichAircraftOrCashcollateralIsPledged
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition 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. + References 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=109980867&loc=SL5624258-113959 + Details
Name: | us-gaap_CollateralAlreadyPostedAggregateFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition 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. + References 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=109980867&loc=d3e41678-113959 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Details
Name: | srt_CounterpartyNameAxis=luv_CounterpartyAlphaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=luv_CounterpartyBMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=luv_CounterpartyCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=luv_CounterpartyDMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=luv_CounterpartyEMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=luv_CounterpartyFMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=luv_CounterpartyOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |