XML 51 R31.htm IDEA: XBRL DOCUMENT
v3.21.1

Financial Derivative Instruments - Offsetting of Derivative Assets (Details) - USD ($) $ in Millions | Mar. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Offsetting Assets [Line Items] |  |  |
Asset derivative contracts, net |  | $ 131 | $ 90
Fuel derivatives | Prepaid expenses and other current assets |  |  |
Offsetting Assets [Line Items] |  |  |
Gross amounts of recognized assets |  | 67 | 13
Gross liability amounts offset in the Balance Sheet |  | (15) | (3)
Asset derivative contracts, net |  | 52 | 10
Fuel derivatives | Other Assets |  |  |
Offsetting Assets [Line Items] |  |  |
Gross amounts of recognized assets |  | 182 | 121
Gross liability amounts offset in the Balance Sheet |  | (57) | (31)
Asset derivative contracts, net | [1] | 125 | 90
Interest rate derivatives | Other Assets |  |  |
Offsetting Assets [Line Items] |  |  |
Gross amounts of recognized assets |  | 6 | 0
Gross liability amounts offset in the Balance Sheet |  | 0 | 0
Asset derivative contracts, net | [1] | $ 6 | $ 0
[1] | The net amounts of derivative assets and liabilities are reconciled to the individual line item amounts presented in the unaudited Condensed Consolidated Balance Sheet in Note 9.

X
- Definition Net fair value 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, elected to be offset against an obligation to return collateral. + References No definition available. + Details
Name: | luv_DerivativeAssetFairValueAmountOffsetAgainstCollateralTotal
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of liability associated with 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, elected to be offset against collateral. + References No definition available. + Details
Name: | luv_DerivativeAssetFairValueGrossLiabilityOffset
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value 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, 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 55 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 + Details
Name: | us-gaap_DerivativeAssetNotSubjectToMasterNettingArrangement
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The net amount as of the balance sheet date of the fair value of derivative assets and derivative liabilities that in accordance with the entity's accounting policy were offset against collateral under a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121590274&loc=d3e41678-113959 + Details
Name: | us-gaap_DerivativeFairValueAmountOffsetAgainstCollateralNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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: | us-gaap_OffsettingAssetsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=luv_OtherAssetsCurrentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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