Consolidated Statements of Cash Flows - USD ($)	4 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2021	Sep. 07, 2021	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net loss	$ (27,200,000)	$ (81,300,000)	$ (192,700,000)	$ (130,900,000)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	144,600,000	194,900,000	449,600,000	497,100,000
Loss on impairment of long-lived assets	0	0	0	2,700,000
Loss on extinguishment of debt	2,100,000	10,700,000	0	0
Provision for loss on receivables	3,600,000	2,100,000	9,100,000	8,400,000
Unrealized loss (gain) on interest rate swaps	0	0	4,400,000	(13,700,000)
Noncash portion of interest expense (income)	(500,000)	4,000,000	7,500,000	5,400,000
Deferred income taxes	(8,600,000)	(21,100,000)	(40,600,000)	(42,300,000)
Pension and other postretirement payments in excess of expense	(7,600,000)	(200,000)	(7,700,000)	(16,100,000)
Stock-based compensation	0	4,300,000	0	0
Other, net	(100,000)	(5,200,000)	(2,400,000)	(1,300,000)
Changes in operating assets and liabilities:
(Increase) decrease in receivables	(138,800,000)	51,100,000	(54,500,000)	(9,100,000)
Increase in inventory, materials, supplies, prepaid expenses and other current assets	(11,800,000)	(29,400,000)	(14,600,000)	(48,100,000)
(Decrease) increase in accounts payable	25,600,000	49,100,000	(54,700,000)	69,200,000
Increase (decrease) in accrued and other current liabilities	(19,500,000)	2,800,000	2,700,000	(1,400,000)
(Increase) decrease in other noncurrent assets	(8,400,000)	2,100,000	(5,100,000)	(5,200,000)
Increase in other noncurrent liabilities	21,600,000	8,800,000	5,000,000	7,300,000
Net cash provided by (used in) operating activities	(25,000,000)	192,700,000	106,000,000	322,000,000
Cash flows from investing activities
Capital expenditures	(127,000,000)	(165,200,000)	(641,400,000)	(482,800,000)
Acquisition of businesses, net of cash acquired	(1,620,700,000)	0	(3,200,000)	(65,500,000)
Purchase of indefinite-lived intangibles	0	0	0	(6,800,000)
Acquisition of fiber assets	(1,700,000)	(50,500,000)	(8,600,000)	0
Proceeds from sale of assets	0	9,100,000	0	2,300,000
Other, net	800,000	(100,000)	(1,000,000)	(900,000)
Net cash used in investing activities	(1,748,600,000)	(206,700,000)	(654,200,000)	(553,700,000)
Cash flows from financing activities
Capital contributions by Red Fiber Parent LLC	1,716,100,000	0	400,000,000	0
Proceeds from issuance of long-term debt	1,145,000,000	23,000,000	211,400,000	2,700,000
Net (decrease) increase in corporate credit facility with initial maturities less than 90 days	0	7,000,000	(70,500,000)	223,000,000
Proceeds from borrowings on receivables facilities	467,500,000	695,400,000	1,706,500,000	1,150,800,000
Payments on receivables facilities	(497,700,000)	(693,400,000)	(1,647,800,000)	(1,116,900,000)
Repayment of debt	(1,004,200,000)	(13,400,000)	(47,800,000)	(20,300,000)
Debt issuance costs	(55,900,000)	(800,000)	(4,000,000)	(700,000)
Dividends paid on preferred stock	(2,400,000)	(7,800,000)	0	0
Other, net	0	(2,000,000)	0	0
Net cash provided by financing activities	1,768,400,000	8,000,000	547,800,000	238,600,000
Effect of exchange rate changes on cash, cash equivalents and restricted cash	100,000	0	0	(100,000)
Net (decrease) increase in cash, cash equivalents and restricted cash	(5,100,000)	(6,000,000)	(400,000)	6,800,000
Cash, cash equivalents and restricted cash at beginning of period	11,200,000	17,200,000	12,900,000	6,100,000
Cash, cash equivalents and restricted cash at end of period	$ 6,100,000	$ 11,200,000	$ 12,500,000	$ 12,900,000