Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net income (loss)	$ 85	$ (11)	$ (37)
Adjustments to reconcile net income (loss) to cash used in operating activities:
Deferred income taxes	0	43	(8)
Depreciation and amortization	72	50	45
Gains recognized on sale-leaseback transactions	(294)	(147)	(87)
Loss on extinguishment of debt	1	0	7
Stock-based compensation	16	14	15
Amortization of cash flow hedges, net of tax	1	1	1
Changes in operating assets and liabilities:
Accounts receivable, net	22	33	(28)
Supplies and other current assets	20	(7)	(40)
Aircraft maintenance deposits	82	(16)	(18)
Other long-term assets	(190)	(163)	(94)
Accounts payable	(15)	47	(4)
Air traffic liability	41	(60)	40
Other liabilities	77	(45)	130
Cash used in operating activities	(82)	(261)	(78)
Cash flows from investing activities:
Capital expenditures	(76)	(51)	(41)
Pre-delivery deposits for flight equipment, net of refunds	3	(36)	(111)
Other	(2)	(3)	(2)
Cash used in investing activities	(75)	(90)	(154)
Cash flows from financing activities:
Proceeds from issuance of debt, net of issuance costs	476	171	273
Principal repayments on debt	(447)	(131)	(266)
Proceeds from sale-leaseback transactions	264	163	71
Proceeds from the exercise of stock options	1	1	1
Tax withholdings on share-based awards	(6)	(5)	(4)
Cash provided by financing activities	288	199	75
Net increase (decrease) in cash, cash equivalents and restricted cash	131	(152)	(157)
Cash, cash equivalents and restricted cash, beginning of period	609	761	918
Cash, cash equivalents and restricted cash, end of period	$ 740	$ 609	$ 761