Business Segment Information - Selected Financial Data for the Company's Business Segment Information (Details) - USD ($) $ in Millions		4 Months Ended	8 Months Ended	12 Months Ended
		Dec. 31, 2021	Sep. 07, 2021	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Revenue		$ 554.4	$ 1,138.7	$ 1,817.3	$ 1,796.0
Operating (loss) income		(9.1)	27.7	(82.7)	(97.3)
Expenditures for long-lived assets	[1]	1,749.4	215.7	653.2	555.1
Depreciation and amortization		144.6	194.9	449.6	497.1
Assets				4,752.0	4,435.6
Operating Segments [Member] | Network [Member]
Segment Reporting Information [Line Items]
Revenue		303.8	664.2	1,002.9	994.3
Operating (loss) income		(6.3)	78.3	(52.7)	(56.2)
Expenditures for long-lived assets		114.8	199.8	627.5	524.9
Depreciation and amortization		113.0	166.9	355.3	393.3
Assets				3,537.6	3,218.5
Operating Segments [Member] | IT Services and Hardware [Member]
Segment Reporting Information [Line Items]
Revenue		259.3	492.4	838.7	827.9
Operating (loss) income		4.0	25.2	(7.1)	(8.4)
Expenditures for long-lived assets		13.9	15.9	25.5	30.1
Depreciation and amortization		31.4	27.9	94.0	103.5
Assets				1,088.7	812.2
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue		(8.7)	(17.9)	(24.3)	(26.2)
Intersegment Eliminations [Member] | Sales [Member]
Segment Reporting Information [Line Items]
Revenue		8.7	17.9	24.3	26.2
Intersegment Eliminations [Member] | Network [Member]
Segment Reporting Information [Line Items]
Revenue		6.5	13.1	16.4	19.3
Intersegment Eliminations [Member] | IT Services and Hardware [Member]
Segment Reporting Information [Line Items]
Revenue		2.2	4.8	7.9	6.9
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating (loss) income		(6.8)	(75.8)	(22.9)	(32.7)
Expenditures for long-lived assets		1,620.7	0.0	0.2	0.1
Depreciation and amortization		$ 0.2	$ 0.1	0.3	0.3
Corporate and Elimination [Member]
Segment Reporting Information [Line Items]
Assets				$ 125.7	$ 404.9

[1] Includes cost of acquisitions in the years ended December 31, 2023 and 2022 and in the Predecessor and Successor periods in 2021 and the purchase of perpetual licenses in the year ended December 31, 2022.