Document And Entity Information (USD $)	12 Months Ended
	Dec. 31, 2011
Document And Entity Information [Abstract]
Entity Registrant Name	Southwest Airlines Co
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0000092380
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding	772,906,217
Public Float	$ 9,119,884,998
Document Type	10-K
Document Period End Date	Dec. 31, 2011
Amendment Flag	false
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q4