Worldwide Pandemic (Details) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended		60 Months Ended	120 Months Ended
	Jun. 30, 2020 USD ($) employees shares	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) employees shares	Jun. 30, 2019 USD ($)	Apr. 19, 2030	Apr. 19, 2030	May 29, 2020 USD ($)	Apr. 21, 2020 USD ($)	Apr. 20, 2020 USD ($) shares	Apr. 09, 2020 $ / shares	Mar. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Proceeds from term loan credit facility	$ 2,683	$ 0	$ 3,683	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			27.00%	23.40%
Total Expected Receipts of Relief Through Payroll Support Program of CARES Act									$ 3,300
Proceeds from Payroll Support Program Grant	2,900		$ 2,900
Cash Raised, Net of Fees			17,300
Unsecured Term Loan Through Payroll Support Program of CARES Act									$ 459
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares										$ 36.47
Proceeds from Payroll Support Program Grant Received in April								$ 1,600
Proceeds from Payroll Support Program Grant Received in May							$ 652
Proceeds from Payroll Support Program Grant Received in June 2020	$ 652		$ 652
Percent of Proceeds from Payroll Support Program Grant Received	90.00%		90.00%
Proceeds from Payroll Support Program Grant Remaining to be Allocated to Payroll Support, Voluntary Separation, net	$ 957		$ 957									$ 0
Percent of Proceeds from Payroll Support Program Grant To be Received in July 2020	10.00%		10.00%
Proceeds from Payroll Support Program Grant To Be Received in July 2020	$ 326		$ 326
Unsecured Term Loan to be Issued Through Payroll Support Program of CARES Act	98		98
Expected Eligibility Amount for Secured Loans Through CARES Act	$ 2,800		$ 2,800
Voluntary Separation Program 2020 Participants | employees	4,200		4,200
Voluntary Separation Program 2020 Accrual for Employees who Accepted through June 30, 2020	$ 307
Proceeds from Payroll Support Program Grant Allocated to Payroll Support, Voluntary Separation, net	1,100
Goodwill	$ 970		$ 970									$ 970
Subsequent Event
Principal Amount Increase on Unsecured Term Loan Through Payroll Support Program of CARES Act						30.00%
Principal Amount Increase on Warrants Issued to Treasury Through Payroll Support Program of CARES Act						10.00%
Minimum
Extended Emergency Time Off Period	6 months
Maximum
Extended Emergency Time Off Period	18 months
Customer Support and Service [Member]
Voluntary Separation Program 2020 Participants | employees	390		390
Ground Operations and Provisioning [Member]
Voluntary Separation Program 2020 Participants | employees	1,060		1,060
Flight Attendants [Member]
Voluntary Separation Program 2020 Participants | employees	725		725
Pilots [Member]
Voluntary Separation Program 2020 Participants | employees	640		640
Pilots [Member] | Maximum
Extended Emergency Time Off Period	5 years
Contract groups [Member]
Voluntary Separation Program 2020 Participants | employees	90		90
Managerial and Administrative [Member]
Voluntary Separation Program 2020 Participants | employees	1,145		1,145
Maintenance [Member]
Voluntary Separation Program 2020 Participants | employees	185		185
LUV Common Stock Warrants
Class of Warrant or Right, Outstanding | shares	2,300,000		2,300,000						1,300,000
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares										$ 36.47
Warrants and Rights Outstanding	$ 35		$ 35
Class of Warrant or Right, Unissued | shares	268,000		268,000
Use Rights [Member]
Indefinite-Lived Domestic Slots and Routes	$ 295		$ 295
CARES Act Unsecured Loan | Unsecured Debt
Stated interest rate	1.00%		1.00%
Unsecured Debt | Forecast | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Basis spread on variable rate (percent) April 21, 2025 and beyond					2.00%
1.0 Payroll Support Program Loan due 2030 | Unsecured Debt
Stated interest rate	1.00%		1.00%
Carrying amount of debt	$ 850		$ 850
Accordian Feature to Amended 364-Day Term Loan Credit Facility [Member] | Amended 364-Day Term Loan Credit Facility
Accordian Feature on Short-term Debt											$ 417