XML 59 R47.htm IDEA: XBRL DOCUMENT
v3.21.2

Fair Value Measurements - Measured on Recurring Basis (Details) - USD ($) $ in Millions | Sep. 30, 2021 | Dec. 31, 2020
--- | --- | ---
Fuel derivatives: |  |
Option contracts | $ 682 | $ 134
Fair Value, Measurements, Recurring |  |
Assets |  |
Treasury bills | 2,249 | 1,800
Fuel derivatives: |  |
Interest rate derivatives (see Note 4) | 1 |
Other available-for-sale securities | 260 | 259
Total assets | 16,946 | 13,727
Liabilities |  |
Interest rate derivatives (see Note 4) | (2) | (6)
Fair Value, Measurements, Recurring | Options Held |  |
Fuel derivatives: |  |
Option contracts | 681 | 134
Fair Value, Measurements, Recurring | Certificates of deposit |  |
Assets |  |
Investments |  | 46
Fair Value, Measurements, Recurring | Time deposits |  |
Assets |  |
Investments | 775 | 425
Fair Value, Measurements, Recurring | Cash Equivalents |  |
Assets |  |
Cash equivalents | 12,790 | 10,663
Fair Value, Measurements, Recurring | Commercial paper |  |
Assets |  |
Cash equivalents | 90 | 90
Fair Value, Measurements, Recurring | Certificates of deposit |  |
Assets |  |
Cash equivalents |  | 10
Fair Value, Measurements, Recurring | Time deposits |  |
Assets |  |
Cash equivalents | 100 | 300
Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) |  |
Assets |  |
Treasury bills | 2,249 | 1,800
Fuel derivatives: |  |
Interest rate derivatives (see Note 4) | 0 |
Other available-for-sale securities | 260 | 259
Total assets | 15,299 | 12,722
Liabilities |  |
Interest rate derivatives (see Note 4) | 0 | 0
Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) | Options Held |  |
Fuel derivatives: |  |
Option contracts | 0 | 0
Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) | Certificates of deposit |  |
Assets |  |
Investments |  | 0
Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) | Time deposits |  |
Assets |  |
Investments | 0 | 0
Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) | Cash Equivalents |  |
Assets |  |
Cash equivalents | 12,790 | 10,663
Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) | Commercial paper |  |
Assets |  |
Cash equivalents | 0 | 0
Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) | Certificates of deposit |  |
Assets |  |
Cash equivalents |  | 0
Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) | Time deposits |  |
Assets |  |
Cash equivalents | 0 | 0
Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) |  |
Assets |  |
Treasury bills | 0 | 0
Fuel derivatives: |  |
Interest rate derivatives (see Note 4) | 1 |
Other available-for-sale securities | 0 | 0
Total assets | 966 | 871
Liabilities |  |
Interest rate derivatives (see Note 4) | (2) | (6)
Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) | Options Held |  |
Fuel derivatives: |  |
Option contracts | 0 | 0
Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) | Certificates of deposit |  |
Assets |  |
Investments |  | 46
Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) | Time deposits |  |
Assets |  |
Investments | 775 | 425
Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) | Cash Equivalents |  |
Assets |  |
Cash equivalents | 0 | 0
Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) | Commercial paper |  |
Assets |  |
Cash equivalents | 90 | 90
Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) | Certificates of deposit |  |
Assets |  |
Cash equivalents |  | 10
Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) | Time deposits |  |
Assets |  |
Cash equivalents | 100 | 300
Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) |  |
Assets |  |
Treasury bills | 0 | 0
Fuel derivatives: |  |
Interest rate derivatives (see Note 4) | 0 |
Other available-for-sale securities | 0 | 0
Total assets | 681 | 134
Liabilities |  |
Interest rate derivatives (see Note 4) | 0 | 0
Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) | Options Held |  |
Fuel derivatives: |  |
Option contracts | 681 | 134
Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) | Certificates of deposit |  |
Assets |  |
Investments |  | 0
Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) | Time deposits |  |
Assets |  |
Investments | 0 | 0
Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) | Cash Equivalents |  |
Assets |  |
Cash equivalents | 0 | 0
Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) | Commercial paper |  |
Assets |  |
Cash equivalents | 0 | 0
Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) | Certificates of deposit |  |
Assets |  |
Cash equivalents |  | 0
Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) | Time deposits |  |
Assets |  |
Cash equivalents | $ 0 | $ 0

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

X
- References No definition available. + Details
Name: | us-gaap_AssetsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References No definition available. + Details
Name: | us-gaap_CashAndCashEquivalentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, before effects of master netting arrangements, of a 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. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 2: http://www.xbrl.org/2003/role/exampleRef -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 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=121570589&loc=SL51823488-111719 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The fair value as of the balance sheet date of firm holdings in debt obligations issued by the US government including short-term Treasury bills, medium-term Treasury notes, and long-term Treasury bonds, as well as debt issued by agencies. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 320 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=35711157&loc=d3e42546-110969 + Details
Name: | us-gaap_FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets. + References No definition available. + Details
Name: | us-gaap_InterestRateDerivativeAssetsAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities. + References No definition available. + Details
Name: | us-gaap_InterestRateDerivativeLiabilitiesAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258 + Details
Name: | us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_LiabilitiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value portion of other assets. + References No definition available. + Details
Name: | us-gaap_OtherAssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_BankTimeDepositsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CashAndCashEquivalentsAxis=us-gaap_CashEquivalentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CashAndCashEquivalentsAxis=us-gaap_CommercialPaperMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CashAndCashEquivalentsAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CashAndCashEquivalentsAxis=us-gaap_BankTimeDepositsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |