CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	$ 1,681	$ 797
Operating Expenses
Wages and benefits	606	493
Variable incentive pay	36	33
PSPGrantRecognized	0	(411)
Aircraft fuel, including hedging gains and losses	347	203
Aircraft maintenance	135	81
Aircraft rent	73	62
Landing fees and other rentals	138	129
Contracted services	78	51
Selling expenses	58	33
Depreciation and amortization	102	97
Food and beverage service	41	23
Third-party regional carrier expense	42	30
Other	152	105
Special items - Impairment charges and other	75	18
Restructuring Charges	0	11
Operating Expenses	1,883	958
Costs and Expenses, Total	1,883	958
Operating Income (Loss)	(202)	(161)
Nonoperating Income (Expense)
Interest income	7	7
Interest expense	(27)	(32)
Interest capitalized	2	3
Other—net	14	10
Nonoperating Income (Expense) Total	(4)	(12)
Income (Loss) Before Income Tax	(206)	(173)
Income tax (benefit) expense	(63)	(42)
Net Income (Loss)	$ (143)	$ (131)
Basic Earnings Per Share (usd per share)	$ (1.14)	$ (1.05)
Diluted Earnings Per Share (usd per share)	$ (1.14)	$ (1.05)
Shares used for computation:
Basic shares (shares)	125,984,000	124,299,000
Diluted shares (shares)	125,984,000	124,299,000
Passenger [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	$ 1,511	$ 659
Mileage plan other revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	112	94
Cargo and Freight [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	58	44
Passenger Revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	1,511	659
Passenger Revenue [Member] | Passenger [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	1,511	659
Mileage Plan Revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	300	178
Mileage Plan Revenue [Member] | Mileage plan other revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	112	94
Cargo and Other Revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	58	44
Cargo and Other Revenue [Member] | Cargo and Freight [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	$ 58	$ 44