[Line Items] for Airport Project [Table]

No definition available.

Name:	luv_AirportProjectLineItems
Namespace Prefix:	luv_
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- Definition

The aggregate costs related to airport construction projects recorded as an asset.

+ References

No definition available.

+ Details

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

- Definition

The total expected cost of the airport modernization project for the city.

+ References

No definition available.

+ Details

Name:	luv_ExpectedTotalCostOfAirportProject
Namespace Prefix:	luv_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Long-term debt securities issued by state, city or local governments or the agencies operated by state, city or local governments.

+ References

No definition available.

+ Details

Name:	luv_MunicipalBondsIssued
Namespace Prefix:	luv_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Municipal Bonds Principal Remaining

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No definition available.

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Name:	luv_MunicipalBondsPrincipalRemaining
Namespace Prefix:	luv_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of Aircrafts Retired from Service

+ References

No definition available.

+ Details

Name:	luv_NumberofAircraftsRetiredfromService
Namespace Prefix:	luv_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate costs related to airport construction projects recorded as a liability.

+ References

No definition available.

+ Details

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

- Definition

Property, Plant and Equipment, Number of Aircraft Purchased

+ References

No definition available.

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Name:	luv_PropertyPlantandEquipmentNumberofAircraftPurchased
Namespace Prefix:	luv_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Proprietary construction reimbursement received after an airport modernization project for the city.

+ References

No definition available.

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

- Definition

The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

+ Details

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

- Details

Name:	luv_AirportProjectAxis=luv_LosAngelesWorldAirportMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	luv_AirportProjectAxis=luv_FortLauderdaleHollywoodInternationalAirportMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	luv_AirportProjectAxis=luv_DALMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	luv_AirportProjectAxis=luv_HOUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	luv_AirportProjectAxis=luv_DALGarageMember
Namespace Prefix:
Data Type:	na
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Period Type:

- Details

Name:	us-gaap_AircraftTypeAxis=us-gaap_B737800Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AircraftTypeAxis=us-gaap_B737700Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AircraftTypeAxis=luv_B737300Member
Namespace Prefix:
Data Type:	na
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Period Type:

- Details

Name:	us-gaap_AircraftTypeAxis=luv_B737500Member
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Commitments and Contingencies (Details)	3 Months Ended	12 Months Ended
Commitments and Contingencies (Details)	Dec. 31, 2010 USD ($)	Dec. 31, 2016 USD ($) aircraft	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Airport Project [Line Items]
Number of aircrafts retired from service \| aircraft		42
Assets constructed for others		$ 1,220,000,000	$ 915,000,000
Depreciation and amortization		1,221,000,000	$ 1,015,000,000	$ 938,000,000
LAX
Airport Project [Line Items]
Expected total airport modernization project cost		526,000,000
Assets constructed for others		344,000,000
FLL
Airport Project [Line Items]
Expected total airport modernization project cost		333,000,000
Assets constructed for others		132,000,000
DAL
Airport Project [Line Items]
Municipal bonds issued	$ 456,000,000
Municipal Bonds Principal Remaining		432,000,000
Assets constructed for others		538,000,000
Airport construction obligation		522,000,000
HOU
Airport Project [Line Items]
Expected total airport modernization project cost		150,000,000
Proprietary Construction Reimbursement		22,000,000
DALGarage [Member]
Airport Project [Line Items]
Assets constructed for others		$ 80,000,000
B-737-800
Airport Project [Line Items]
Number of Aircrafts Purchased \| aircraft		38
B-737-700
Airport Project [Line Items]
Number of Aircrafts Purchased \| aircraft		23
B737-300
Airport Project [Line Items]
Number of aircrafts retired from service \| aircraft		31
B737-500
Airport Project [Line Items]
Number of aircrafts retired from service \| aircraft		11