Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating revenues:
Total operating revenues	$ 3,589	$ 3,326	$ 2,060
Operating expenses:
Aircraft fuel	1,130	1,160	575
Salaries, wages and benefits	858	715	616
Aircraft rent	554	556	530
Station operations	516	422	384
Maintenance, materials and repairs	179	146	119
Sales and marketing	164	164	109
Depreciation and amortization	50	45	38
CARES Act credits	0	0	(295)
Transaction and merger-related costs, net	1	10	0
Other operating	140	153	101
Total operating expenses	3,592	3,371	2,177
Operating income (loss)	(3)	(45)	(117)
Other income (expense):
Interest expense	(29)	(21)	(33)
Capitalized interest	28	11	4
Interest income and other	36	10	2
Total other income (expense)	35	0	(27)
Income (loss) before income taxes	32	(45)	(144)
Income tax expense (benefit)	43	(8)	(42)
Net income (loss)	$ (11)	$ (37)	$ (102)
Earnings (loss) per share:
Basic (in dollars per share)	$ (0.05)	$ (0.17)	$ (0.48)
Diluted (in dollars per share)	$ (0.05)	$ (0.17)	$ (0.48)
Passenger
Operating revenues:
Total operating revenues	$ 3,509	$ 3,248	$ 2,000
Other
Operating revenues:
Total operating revenues	$ 80	$ 78	$ 60