Fair Value Measurements Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2008
Fair Value Disclosures [Abstract]
Auction frequency, min	30 days
Auction frequency, max	35 days
Available For Sale Securities Unrealized Loss	$ 12
Auction Rate Securities, Lower Remaining Maturity Range (in years)	6 years
Auction Rate Securities, Higher Remaining Maturity Range (in years)	35 years
Auction Rate Securities at Failed Auctions		463
Auction Rate Securities Sold At Par After Failed Auctions	$ 413

Auction Rate Securities Auction Frequency, Max

No definition available.

Name:	luv_AuctionRateSecuritiesAuctionFrequencyMax
Namespace Prefix:	luv_
Data Type:	xbrli:durationItemType
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- Definition

The time interval, in days, between each auction process for auction rate securities in order to meet Level 1 input requirements.

+ References

No definition available.

+ Details

Name:	luv_AuctionRateSecuritiesAuctionFrequencyMin
Namespace Prefix:	luv_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The high end of the range of time remaining until maturity for auction rate securities outstanding.

+ References

No definition available.

+ Details

Name:	luv_AuctionRateSecuritiesHigherRemainingMaturityRange
Namespace Prefix:	luv_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The low end of the range of time remaining until maturity for auction rate securities held.

+ References

No definition available.

+ Details

Name:	luv_AuctionRateSecuritiesLowerRemainingMaturityRange
Namespace Prefix:	luv_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The value of securities held, for which the interest rate resets through an auction process, that are categorized neither as trading nor held-to-maturity, that failed to be liquidated through auction.

+ References

No definition available.

+ Details

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

- Definition

This item represents the gross unrealized losses for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLosses1
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The aggregate value of securities held, which were categorized neither as trading nor held-to-maturity, for which the interest rate reset through an auction process, that failed to be liquidated through auction, and which were sold at par value during the period.

+ References

No definition available.

+ Details

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

- Details

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