Consolidated Statements of Cash Flows - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2021	Sep. 07, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net loss	$ (27.2)	$ (81.3)	$ (55.6)	$ (66.6)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	144.6	194.9	293.4	304.9
Loss on extinguishment of debt	2.1	10.7	0.0	0.0
Provision for loss on receivables	3.6	2.1	14.7	12.5
Noncash portion of interest (income) expense	(0.5)	4.0	5.5	6.2
Deferred income taxes	(8.6)	(21.1)	(27.7)	(10.9)
Pension and other postretirement payments (in excess of) less than expense	(7.6)	(0.2)	1.0	(0.1)
Stock-based compensation	0.0	4.3	5.6	7.4
Other, net	(0.1)	(5.2)	0.4	(5.0)
Changes in operating assets and liabilities:
(Increase) decrease in receivables	(138.8)	51.1	(74.9)	27.6
(Increase) decrease in inventory, materials, supplies, prepaid expenses and other current assets	(11.8)	(29.4)	5.0	5.0
Increase (decrease) in accounts payable	25.6	49.1	15.8	(40.0)
(Decrease) increase in accrued and other current liabilities	(19.5)	2.8	6.8	13.0
(Increase) decrease in other noncurrent assets	(8.4)	2.1	13.7	9.3
Increase (decrease) in other noncurrent liabilities	21.6	8.8	2.4	(4.2)
Net cash (used in) provided by operating activities	(25.0)	192.7	206.1	259.1
Cash flows from investing activities
Capital expenditures	(127.0)	(165.2)	(223.6)	(223.8)
Acquisition of business	(1,620.7)	0.0	0.0	0.0
Acquisition of Paniolo fiber assets	(1.7)	(50.5)	0.0	0.0
Wireless spectrum license purchase	0.0	0.0	(6.4)	0.0
Proceeds from sale of assets	0.0	9.1	3.5	0.0
Other, net	0.8	(0.1)	0.1	0.5
Net cash used in investing activities	(1,748.6)	(206.7)	(226.4)	(223.3)
Cash flows from financing activities
Capital contributions by Red Fiber Parent LLC	1,716.1	0.0	0.0	0.0
Proceeds from issuance of long-term debt	1,145.0	23.0	0.0	0.0
Net (decrease) increase in corporate credit and receivables facilities with initial maturities less than 90 days	(30.2)	9.0	60.2	(6.1)
Repayment of debt	(1,004.2)	(13.4)	(22.4)	(21.5)
Debt issuance costs	(55.9)	(0.8)	(0.7)	(0.8)
Dividends paid on preferred stock	(2.4)	(7.8)	(10.4)	(10.4)
Other, net	0.0	(2.0)	(1.1)	(0.8)
Net cash provided by (used in) financing activities	1,768.4	8.0	25.6	(39.6)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	0.1	0.0	0.3	0.0
Net (decrease) increase in cash, cash equivalents and restricted cash	(5.1)	(6.0)	5.6	(3.8)
Cash, cash equivalents and restricted cash at beginning of period	11.2	17.2	11.6	15.4
Cash, cash equivalents and restricted cash at end of period	$ 6.1	$ 11.2	$ 17.2	$ 11.6