v3.25.4

Cover Page - USD ($)	12 Months Ended
Cover Page - USD ($)	Dec. 31, 2025	Feb. 03, 2026	Jun. 30, 2025
Cover [Abstract]
Document Type	10-K/A
Document Annual Report	true
Document Period End Date	Dec. 31, 2025
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	1-7259
Entity Registrant Name	SOUTHWEST AIRLINES CO.
Entity Incorporation, State or Country Code	TX
Entity Tax Identification Number	74-1563240
Entity Address, Address Line One	P.O. Box 36611
Entity Address, City or Town	Dallas,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75235-1611
City Area Code	214
Local Phone Number	792-4000
Title of 12(b) Security	Common Stock ($1.00 par value)
Trading Symbol	LUV
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 16,890,396,912
Entity Common Stock, Shares Outstanding		491,317,990
Documents Incorporated by Reference	Portions of the Definitive Proxy Statement for the Company’s Annual Meeting of Shareholders to be held May 07, 2026, are incorporated into Part III of this Annual Report on Form 10-K.
Entity Central Index Key	0000092380
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
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SOUTHWEST AIRLINES CO 10-K/A