Line of Credit Facility, Maximum Amount Outstanding at Period End

No definition available.

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

- Definition

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
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-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
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+ Details

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

- Definition

Carrying amount, (original cost adjusted for any previously recognized amortization and impairment) as of the balance sheet date, of domestic slots, route authorities, airport operating and gate lease rights and related intangibles.

+ References

No definition available.

+ Details

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

- Definition

The cash inflow from a borrowing supported by a written promise to pay an obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
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-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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-Paragraph 1
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-Name Accounting Standards Codification
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShortTermDebtTypeAxis=us-gaap_NotesPayableToBanksMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=luv_TermLoanAgreementDue2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Worldwide Pandemic (Details) - USD ($) $ in Millions	3 Months Ended
Worldwide Pandemic (Details) - USD ($) $ in Millions	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Proceeds from term loan credit facility	$ 1,000	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	34.30%	23.10%
Goodwill	$ 970		$ 970
Use Rights [Member]
Indefinite-Lived Domestic Slots and Routes	295
364-Day Term Loan Credit Facility
364-Day Term Loan Credit Facility	1,000
Total Funds Outstanding Amended 364-Day Term Loan Credit Facility [Member]
364-Day Term Loan Credit Facility	3,300
Notes Payable to Banks \| Term Loan Agreement Due 2021
364-Day Term Loan Credit Facility	1,000
Revolving Credit Facility
Revolving Credit Facility, Maximum Amount Outstanding at Period End	$ 1,000