Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net income (loss)	$ (11,000,000)	$ (37,000,000)	$ (102,000,000)
Deferred income taxes	43,000,000	(8,000,000)	(32,000,000)
Depreciation and amortization	50,000,000	45,000,000	38,000,000
Gains recognized on sale-leaseback transactions	(147,000,000)	(87,000,000)	(60,000,000)
Loss on extinguishment of debt	0	7,000,000	0
Warrant liability unrealized loss	0	0	22,000,000
Stock-based compensation	14,000,000	15,000,000	11,000,000
Amortization of cash flow hedges, net of tax	1,000,000	1,000,000	1,000,000
Changes in operating assets and liabilities:
Accounts receivable	33,000,000	(28,000,000)	(14,000,000)
Supplies and other current assets	(7,000,000)	(40,000,000)	174,000,000
Aircraft maintenance deposits	(16,000,000)	(18,000,000)	(20,000,000)
Other long-term assets	(163,000,000)	(94,000,000)	(37,000,000)
Accounts payable	47,000,000	(4,000,000)	13,000,000
Air traffic liability	(60,000,000)	40,000,000	138,000,000
Other liabilities	(45,000,000)	130,000,000	84,000,000
Cash provided by (used in) operating activities	(261,000,000)	(78,000,000)	216,000,000
Cash flows from investing activities:
Capital expenditures	(51,000,000)	(41,000,000)	(27,000,000)
Pre-delivery deposits for flight equipment, net of refunds	(36,000,000)	(111,000,000)	(36,000,000)
Other	(3,000,000)	(2,000,000)	(4,000,000)
Cash used in investing activities	(90,000,000)	(154,000,000)	(67,000,000)
Cash flows from financing activities:
Proceeds from issuance of debt, net of issuance costs	171,000,000	273,000,000	163,000,000
Principal repayments on debt	(131,000,000)	(266,000,000)	(97,000,000)
Proceeds from sale-leaseback transactions	163,000,000	71,000,000	59,000,000
Proceeds from initial public offering, net of offering costs, underwriting discounts and commissions	0	0	266,000,000
Proceeds from the exercise of stock options	1,000,000	1,000,000	3,000,000
Tax withholdings on share-based awards	(5,000,000)	(4,000,000)	(3,000,000)
Cash provided by financing activities	199,000,000	75,000,000	391,000,000
Net increase (decrease) in cash, cash equivalents and restricted cash	(152,000,000)	(157,000,000)	540,000,000
Cash, cash equivalents and restricted cash, beginning of period	761,000,000	918,000,000	378,000,000
Cash, cash equivalents and restricted cash, end of period	$ 609,000,000	$ 761,000,000	$ 918,000,000