Consolidated Statements of Cash Flows - USD ($)	4 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2021	Sep. 07, 2021	Dec. 31, 2022	Dec. 31, 2020
Cash flows from operating activities
Net loss	$ (27,200,000)	$ (81,300,000)	$ (130,900,000)	$ (55,600,000)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	144,600,000	194,900,000	497,100,000	293,400,000
Loss on impairment of long-lived assets	0	0	2,700,000	0
Loss on extinguishment of debt	2,100,000	10,700,000	0	0
Provision for loss on receivables	3,600,000	2,100,000	8,400,000	14,700,000
Unrealized gain on interest rate swaps	0	0	(13,700,000)	0
Noncash portion of interest expense (income)	(500,000)	4,000,000.0	5,400,000	5,500,000
Deferred income taxes	(8,600,000)	(21,100,000)	(42,300,000)	(27,700,000)
Pension and other postretirement payments (in excess of) less than expense	(7,600,000)	(200,000)	(16,100,000)	1,000,000.0
Stock-based compensation	0	4,300,000	0	5,600,000
Other, net	(100,000)	(5,200,000)	(1,300,000)	400,000
Changes in operating assets and liabilities:
(Increase) decrease in receivables	(138,800,000)	51,100,000	(9,100,000)	(74,900,000)
(Increase) decrease in inventory, materials, supplies, prepaid expenses and other current assets	(11,800,000)	(29,400,000)	(48,100,000)	5,000,000.0
Increase in accounts payable	25,600,000	49,100,000	69,200,000	15,800,000
(Decrease) increase in accrued and other current liabilities	(19,500,000)	2,800,000	(1,400,000)	6,800,000
(Increase) decrease in other noncurrent assets	(8,400,000)	2,100,000	(5,200,000)	13,700,000
Increase in other noncurrent liabilities	21,600,000	8,800,000	6,500,000	2,400,000
Net cash provided by (used in) operating activities	(25,000,000.0)	192,700,000	321,200,000	206,100,000
Cash flows from investing activities
Capital expenditures	(127,000,000.0)	(165,200,000)	(482,800,000)	(223,600,000)
Acquisition of business, net of cash acquired	(1,620,700,000)	0	(65,500,000)	0
Purchase of indefinite-lived intangibles	0	0	(6,800,000)	0
Acquisition of Paniolo fiber assets	(1,700,000)	(50,500,000)	0	0
Wireless spectrum license purchase	0	0	0	(6,400,000)
Proceeds from sale of assets	0	9,100,000	2,300,000	3,500,000
Other, net	800,000	(100,000)	(900,000)	100,000
Net cash used in investing activities	(1,748,600,000)	(206,700,000)	(553,700,000)	(226,400,000)
Cash flows from financing activities
Capital contributions by Red Fiber Parent LLC	1,716,100,000	0	0	0
Proceeds from issuance of long-term debt	1,145,000,000.0	23,000,000.0	2,700,000	0
Net increase in corporate credit facility with initial maturities less than 90 days	0	7,000,000.0	223,000,000.0	10,000,000.0
Proceeds from borrowings on Receivables Facility	467,500,000	695,400,000	1,150,800,000	939,100,000
Payments on Receivables Facility	(497,700,000)	(693,400,000)	(1,116,900,000)	(888,900,000)
Repayment of debt	(1,004,200,000)	(13,400,000)	(20,300,000)	(22,400,000)
Debt issuance costs	(55,900,000)	(800,000)	(700,000)	(700,000)
Dividends paid on preferred stock	(2,400,000)	(7,800,000)	0	(10,400,000)
Other, net	0	(2,000,000.0)	800,000	(1,100,000)
Net cash provided by financing activities	1,768,400,000	8,000,000.0	239,400,000	25,600,000
Effect of exchange rate changes on cash, cash equivalents and restricted cash	100,000	0	(100,000)	300,000
Net increase (decrease) in cash, cash equivalents and restricted cash	(5,100,000)	(6,000,000.0)	6,800,000	5,600,000
Cash, cash equivalents and restricted cash at beginning of period	11,200,000	17,200,000	6,100,000	11,600,000
Cash, cash equivalents and restricted cash at end of period	$ 6,100,000	$ 11,200,000	$ 12,900,000	$ 17,200,000