Financial Derivative Instruments Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended				3 Months Ended		3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Southwest Airlines	Sep. 30, 2013 AirTran Airways	Sep. 30, 2013 Fuel derivatives	Dec. 31, 2012 Fuel derivatives	Sep. 30, 2013 Cash Flow Hedging		Sep. 30, 2012 Cash Flow Hedging		Sep. 30, 2013 Cash Flow Hedging		Sep. 30, 2012 Cash Flow Hedging		Sep. 30, 2013 Cash Flow Hedging Fuel derivatives		Sep. 30, 2012 Cash Flow Hedging Fuel derivatives		Sep. 30, 2013 Cash Flow Hedging Fuel derivatives		Sep. 30, 2012 Cash Flow Hedging Fuel derivatives		Sep. 30, 2013 Cash Flow Hedging Interest rate derivatives		Sep. 30, 2012 Cash Flow Hedging Interest rate derivatives		Sep. 30, 2013 Cash Flow Hedging Interest rate derivatives		Sep. 30, 2012 Cash Flow Hedging Interest rate derivatives		Sep. 30, 2013 Remainder of 2013
Derivative [Line Items]
Total Collateral Already Posted Aggregate Fair Value								$ 0
Percent of fuel consumption hedged	78.00%		78.00%																														48.00%
Gain (Loss) On Derivative Due To Loss Of Hedge Accounting							28
Cash collateral deposits provided to counterparty - noncurrent					32	1
Premiums paid for fuel derivative contracts	22	15	39	33
Current Unrealized Net Gains (Losses) in OCI	(15)		(15)
Cumulative ineffectiveness recognized for unsettled hedges	(69)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net									(28)	[1]	(29)	[1]	(102)	[1]	(89)	[1]	(24)	[1],[2]	(25)	[1],[2]	(88)	[1],[2]	(76)	[1],[2]	(4)	[1],[2]	(4)	[1],[2]	(14)	[1],[2]	(13)	[1],[2]
Maximum sum of derivatives of counterparty to be included in other (less than $20 million)	$ 20		$ 20
Cash collateral provided as a percentage of derivative contract value (in hundredths)	100.00%		100.00%

[1] Amounts related to fuel derivative contracts and interest rate derivatives are included in Fuel and oil and Interest expense, respectively.

[2] Net of tax