Consolidated Statements Of Cash Flows - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022
Cash flows provided from (used by) operating activities:
Net Income	$ 4,541	$ 414	$ 29	$ 441
Adjustments to reconcile net loss to net cash provided from (used by) operating activities:
Depreciation and amortization	506	734	1,415	1,182
Pension settlement costs				55
Stock-based compensation expense	(1)	18	108	82
Non-cash reorganization items	(5,467)
Amortization of (premium) discount	1	(18)	(25)	(28)
Lease Impairment				44
Bad debt expense		14	35	26
Other adjustments			12
Deferred income taxes	(148)	81	78	164
Change in accounts receivable	36	45	(43)	(7)
Change in long-term pension and other postretirement liabilities	(12)	21	(325)	(656)
Change in accounts payable and other liabilities	(156)	94	55	51
Change in prepaid expenses, income taxes, and other assets	46	48	5	47
Net cash provided from (used by) operating activities	(654)	1,451	1,344	1,401
Cash flows provided from (used by) investing activities:
Capital expenditures	(500)	(1,205)	(3,211)	(2,738)
Purchase of short-term investments			(2,275)	(4,350)
Sale of short-term investments			2,950	2,600
Purchase of long-term investments			(62)
Proceeds on sale of assets	9	7	36	13
Other	1	5	6	7
Net cash used by investing activities	(490)	(1,193)	(2,556)	(4,468)
Cash flows provided from (used by) financing activities:
Long-term debt principal payments	(1)	(17)	(68)	(14)
Net proceeds from long-term debt borrowings	225	1,000	2,278	1,200
Payments of vendor financing			(5)
Premium paid to retire debt			(10)
Financing costs paid	(4)	(13)	(62)	(17)
Finance lease obligation payments	(7)	(13)	(25)	(19)
Proceeds from financing lease transactions		23	30	70
Taxes paid on behalf of employees for shares withheld			(9)	(8)
Other	(16)			(1)
Net cash provided from financing activities	197	980	2,129	1,211
Increase (Decrease) in cash, cash equivalents, and restricted cash	(947)	1,238	917	(1,856)
Cash, cash equivalents, and restricted cash at the beginning of the period	1,887	940	322	2,178
Cash, cash equivalents, and restricted cash at the end of the period	940	2,178	1,239	322
Supplemental cash flow information: Cash paid during the period for:
Interest	84	281	711	512
Income tax payments, net	9	28		8
Reorganization items, net	1,397
Non-cash investing activities:
Increase (Decrease) in capital expenditures due to changes in accounts payable and accrued liabilities	(5)	(26)	(326)	$ 797
Increase in capital expenditures due to changes in vendor financing			$ 255
Financial Designation, Predecessor and Successor [Fixed List]	Predecessor	Successor	Successor	Successor