XML 65 R49.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Commitments and Contingencies - Airport Projects (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2010 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Airport Project [Line Items] |  |  |  |  |
Assets constructed for others |  |  | $ 1,768 | $ 1,543 |
Assets constructed for others, net | [1] |  | 1,637 | 1,448 |
Depreciation and amortization |  |  | 1,201 | 1,218 | $ 1,221
Construction obligation | [2] |  | 1,701 | 1,390 |
Los Angeles World Airport Terminal 1 |  |  |  |  |
Airport Project [Line Items] |  |  |  |  |
Expected total airport modernization project cost |  |  | 526 |  |
Contractual Obligation |  |  | 111 |  |
Expected Total Cost Of Airport Project Nonproprietary |  |  | 510 |  |
Assets constructed for others |  |  | 485 | 433 |
Assets constructed for others, net | [1] |  | 459 | 417 |
Construction obligation | [2] |  | 476 | 433 |
Los Angeles World Airport Terminal 1.5 |  |  |  |  |
Airport Project [Line Items] |  |  |  |  |
Expected total airport modernization project cost |  |  | 479 |  |
Contractual Obligation |  |  | 106 |  |
Assets constructed for others | [3] |  | 99 | 31 |
Assets constructed for others, net | [1],[3] |  | 99 | 31 |
Construction obligation | [2],[3] |  | 99 | 31 |
FLL |  |  |  |  |
Airport Project [Line Items] |  |  |  |  |
Expected total airport modernization project cost |  |  | 333 |  |
Assets constructed for others |  |  | 313 | 258 |
Assets constructed for others, net | [1] |  | 304 | 256 |
Construction obligation | [2] |  | 308 | 258 |
DAL |  |  |  |  |
Airport Project [Line Items] |  |  |  |  |
Municipal bonds issued |  | $ 456 |  |  |
Municipal Bonds Principal Remaining |  |  | 416 |  |
Assets constructed for others |  |  | 545 | 543 |
Assets constructed for others, net | [1] |  | 460 | 474 |
Construction obligation | [2] |  | 502 | 516 |
HOU |  |  |  |  |
Airport Project [Line Items] |  |  |  |  |
Assets constructed for others | [4] |  | 126 | 126 |
Assets constructed for others, net | [1],[4] |  | 115 | 118 |
Construction obligation | [2],[4] |  | 116 | 0 |
DALGarage |  |  |  |  |
Airport Project [Line Items] |  |  |  |  |
Assets constructed for others |  |  | 200 | 152 |
Assets constructed for others, net | [1] |  | 200 | 152 |
Construction obligation | [2] |  | $ 200 | $ 152 |
[1] | Net of accumulated depreciation.
[2] | Construction obligation will be reduced through future facility rent payments. These future payments are not fixed per the lease agreement, but are variable and fluctuate based on various market and other factors outside the control of the Company.
[3] | Project still in progress.
[4] | Project completed in 2015 at Houston William P. Hobby Airport ("HOU").

X
- Definition [Line Items] for Airport Project [Table] + References No definition available. + Details
Name: | luv_AirportProjectLineItems
Namespace Prefix: | luv_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- 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

X
- Definition Assets Constructed For Others Net + References No definition available. + Details
Name: | luv_AssetsConstructedForOthersNet
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Construction Obligation, Noncurrent + References No definition available. + Details
Name: | luv_ConstructionObligationNoncurrent
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- 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

X
- Definition Expected Total Cost Of Airport Project Nonproprietary + References No definition available. + Details
Name: | luv_ExpectedTotalCostOfAirportProjectNonproprietary
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- 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

X
- Definition Municipal Bonds Principal Remaining + References No definition available. + Details
Name: | luv_MunicipalBondsPrincipalRemaining
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments. + References No definition available. + Details
Name: | us-gaap_ContractualObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- 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://fasb.org/us-gaap/role/ref/legacyRef -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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 + Details
Name: | us-gaap_DepreciationAndAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | luv_AirportProjectAxis=luv_LosAngelesWorldAirportMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | luv_AirportProjectAxis=luv_LosAngelesWorldAirportTerminal1.5Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | luv_AirportProjectAxis=luv_FortLauderdaleHollywoodInternationalAirportMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | luv_AirportProjectAxis=luv_DALMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | luv_AirportProjectAxis=luv_HOUMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | luv_AirportProjectAxis=luv_DALGarageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |