CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	$ 2,828	$ 1,953	$ 7,167	$ 4,277
Operating Expenses
Wages and benefits	686	578	1,931	1,581
Variable incentive pay	48	42	140	109
PSPGrantRecognized	0	0	0	(914)
Aircraft fuel, including hedging gains and losses	877	376	2,000	853
Aircraft maintenance	92	89	331	272
Aircraft rent	76	64	222	188
Landing fees and other rentals	161	141	435	414
Contracted services	83	62	243	167
Selling expenses	82	49	218	123
Depreciation and amortization	104	99	310	294
Food and beverage service	52	39	143	97
Third-party regional carrier expense	53	39	145	106
Other	207	126	536	348
Special items - Impairment charges and other	155	(9)	376	5
Special items - labor ratification bonus	90	0	90	0
Restructuring Charges	0	0	0	(12)
Operating Expenses	2,766	1,695	7,120	3,631
Costs and Expenses, Total	2,766	1,695	7,120	3,631
Operating Income (Loss)	62	258	47	646
Nonoperating Income (Expense)
Interest income	17	6	35	19
Interest expense	(31)	(30)	(84)	(101)
Interest capitalized	3	3	8	9
Other—net	14	8	38	27
Nonoperating Income (Expense) Total	3	(13)	(3)	(46)
Income (Loss) Before Income Tax	65	245	44	600
Income tax (benefit) expense	25	51	8	140
Net Income (Loss)	$ 40	$ 194	$ 36	$ 460
Basic Earnings Per Share (usd per share)	$ 0.32	$ 1.55	$ 0.28	$ 3.69
Diluted Earnings Per Share (usd per share)	$ 0.31	$ 1.53	$ 0.28	$ 3.64
Shares used for computation:
Basic shares (shares)	126,783,000	125,250,000	126,440,000	124,846,000
Diluted shares (shares)	128,370,000	127,188,000	128,087,000.000	126,325,000
Passenger [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	$ 2,615	$ 1,774	$ 6,544	$ 3,785
Mileage plan other revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	146	120	433	332
Cargo and Freight [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	67	59	190	160
Passenger Revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	2,615	1,774	6,544	3,785
Passenger Revenue [Member] | Passenger [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	2,615	1,774	6,544	3,785
Mileage Plan Revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	382	310	1,104	760
Mileage Plan Revenue [Member] | Mileage plan other revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	146	120	433	332
Cargo and Other Revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	67	59	190	160
Cargo and Other Revenue [Member] | Cargo and Freight [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	$ 67	$ 59	$ 190	$ 160