Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands		2 Months Ended	7 Months Ended	9 Months Ended
		Mar. 12, 2025	Sep. 30, 2025	Sep. 30, 2024
Operating activities:
Net income (loss)		$ 72,216	$ (574,243)	$ (643,805)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operations:
Losses reclassified from other comprehensive income		34	0	55
Share-based compensation		1,233	4,366	5,374
Allowance for doubtful accounts (recoveries)		0	(547)	822
Amortization of debt issuance costs		1,003	2,296	10,625
Amortization of debt fair value adjustment (fresh start accounting)		0	19,421	0
Depreciation and amortization		54,853	132,515	249,860
Accretion of 8.00% senior secured notes		0	0	3,157
Amortization of debt discount		0	219	8,650
Deferred income tax expense (benefit)		17,481	(3,420)	(36,208)
Loss (gain) on disposal of assets		11,655	(114,041)	(13,885)
Reorganization items		(421,464)	125,983	0
Changes in operating assets and liabilities:
Accounts receivable, net		(22,726)	87,842	(20,972)
Deposits and other assets		13,597	(242,361)	(59,303)
Deferred heavy maintenance		(26,736)	(24,735)	(74,739)
Income tax receivable		0	0	(4,193)
Accounts payable		14,240	208,243	(23,508)
Air traffic liability		81,855	(144,937)	75,807
Other liabilities		(20,165)	(131,476)	(109,826)
Other		(767)	(897)	(2,203)
Net cash provided by (used in) operating activities		(223,691)	(655,772)	(634,292)
Investing activities:
Purchase of available-for-sale investment securities		(25,072)	(27,996)	(132,040)
Proceeds from the maturity and sale of available-for-sale investment securities		24,750	148,186	131,100
Proceeds from sale of property and equipment		0	271,261	164,313
Pre-delivery deposit and other payments on flight equipment		(1,411)	(4,234)	(3,648)
Pre-delivery deposit refunds on flight equipment		26,434	13,217	349,830
Capitalized interest		(1,331)	(550)	(13,171)
Assets under construction for others		2,875	8,894	1,376
Purchase of property and equipment		(7,204)	(26,007)	(91,754)
Net cash provided by (used in) investing activities		19,041	382,771	406,006
Financing activities:
Proceeds from issuance of long-term debt		0	490,000	123,500
Proceeds from issuance of common stock and warrants		350,000	0	0
Payments on debt obligations		(634,506)	(63,525)	(151,517)
Payments for the early extinguishment of debt		0	(61,040)	(124,007)
Payments on finance lease obligations		(37)	(128)	(257)
Reimbursement for assets under construction for others		(2,573)	(9,196)	(1,159)
Repurchase of common stock		0	0	(649)
Debt and equity financing costs		(13,456)	(1,738)	(8,603)
Net cash provided by (used in) financing activities		(300,572)	354,373	(162,692)
Net increase (decrease) in cash, cash equivalents, and restricted cash		(505,222)	81,372	(390,978)
Cash, cash equivalents, and restricted cash at beginning of period	[1]	1,070,447	565,225	984,611
Cash, cash equivalents, and restricted cash at end of period	[1]	565,225	646,597	593,633
Cash payments for:
Interest, net of capitalized interest		64,790	60,907	126,127
Income taxes paid (received), net		152	1,624	7,384
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases		96,575	291,878	388,328
Financing cash flows for finance leases		5	13	25
Non-cash transactions:
Capital expenditures funded by finance lease borrowings		0	0	274
Capital expenditures funded by operating lease borrowings		$ 98,385	$ 314,612	$ 1,177,514

[1] (1) The sum of cash and cash equivalents and restricted cash on the Company's condensed consolidated balance sheets equals cash, cash equivalents, and restricted cash in the Company's condensed consolidated statement of cash flows.