Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net loss	$ (129,300,000)	$ (192,700,000)	$ (130,900,000)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	344,600,000	449,600,000	497,100,000
Loss on impairment of long-lived assets	3,100,000	0	2,700,000
Provision for credit loss on receivables	9,700,000	9,100,000	8,400,000
Unrealized (gain) loss on interest rate swaps	(1,200,000)	4,400,000	(13,700,000)
Noncash portion of interest expense	8,700,000	7,500,000	5,400,000
Deferred income taxes	15,500,000	(40,600,000)	(42,300,000)
Pension and other postretirement payments in excess of expense	(14,400,000)	(7,700,000)	(16,100,000)
Gain on sale of discontinued operations	(93,700,000)	0	0
Other, net	(10,400,000)	(2,400,000)	(1,300,000)
Changes in operating assets and liabilities:
Decrease (increase) in receivables	87,000,000	(54,500,000)	(9,100,000)
Decrease (increase) in inventory, materials, supplies, prepaid expenses and other current assets	3,900,000	(14,600,000)	(48,100,000)
(Decrease) increase in accounts payable	(20,400,000)	(54,700,000)	69,200,000
Increase (decrease) in accrued and other current liabilities	31,200,000	2,700,000	(1,400,000)
Increase in other noncurrent assets	(19,200,000)	(5,100,000)	(5,200,000)
Increase in other noncurrent liabilities	21,700,000	5,000,000	7,300,000
Net cash provided by operating activities	236,800,000	106,000,000	322,000,000
Cash flows from investing activities
Capital expenditures	(553,500,000)	(641,400,000)	(482,800,000)
Acquisition of businesses, net of cash acquired	0	(3,200,000)	(65,500,000)
Proceeds from sale of discontinued operations, net of cash divested	672,200,000	0	0
Insurance proceeds received for damage to equipment	7,600,000	300,000	400,000
Purchase of indefinite-lived intangibles	0	0	(6,800,000)
Acquisition of fiber and cable assets	(1,500,000)	(8,600,000)	0
Other, net	(500,000)	(1,300,000)	1,000,000
Net cash provided by (used in) investing activities	124,300,000	(654,200,000)	(553,700,000)
Cash flows from financing activities
Capital contributions by Red Fiber Parent LLC	200,000,000	400,000,000	0
Proceeds from issuance of long-term debt	331,700,000	211,400,000	2,700,000
Net (decrease) increase in corporate credit facility with initial maturities less than 90 days	(152,500,000)	(70,500,000)	223,000,000
Proceeds from borrowings on receivables facilities	1,279,900,000	1,706,500,000	1,150,800,000
Payments on receivables facilities	(1,525,400,000)	(1,647,800,000)	(1,116,900,000)
Repayment of debt	(36,200,000)	(47,800,000)	(20,300,000)
Debt issuance costs	(5,400,000)	(4,000,000)	(700,000)
Net cash provided by financing activities	92,100,000	547,800,000	238,600,000
Effect of exchange rate changes on cash, cash equivalents and restricted cash	100,000	0	(100,000)
Net increase (decrease) in cash, cash equivalents and restricted cash	453,300,000	(400,000)	6,800,000
Cash, cash equivalents and restricted cash at beginning of period	12,500,000	12,900,000	6,100,000
Cash, cash equivalents and restricted cash at end of period	$ 465,800,000	$ 12,500,000	$ 12,900,000