Consolidated Statements of Equity (Deficit) - USD ($) shares in Millions, $ in Millions	Total	Cumulative Convertible Preferred Shares [Member]	Common Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total [Member]	Noncontrolling Interests [Member]
Beginning Balance, Equity (Deficit) at Dec. 31, 2019	$ (140.0)	$ 129.4	$ 0.5	$ 2,676.2	$ (2,776.0)	$ (170.1)	$ (140.0)	$ 0.0
Beginning Balance, Shares at Dec. 31, 2019		3.1
Beginning Balance, Shares at Dec. 31, 2019			50.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(55.6)				(55.6)		(55.6)
Other comprehensive income	10.4					10.4	10.4
Shares issued under employee plans	0.0		$ 0.0	0.0
Shares issued under employee plans, Shares			0.3
Shares purchased under employee plans and other	(1.1)			(1.1)			(1.1)
Stock-based compensation	5.6			5.6			5.6
Dividends on preferred stock	(10.4)			(10.4)			(10.4)
Ending Balance, Equity (Deficit) at Dec. 31, 2020	(191.1)	$ 129.4	$ 0.5	2,670.3	(2,831.6)	(159.7)	(191.1)	0.0
Ending Balance, Shares at Dec. 31, 2020		3.1
Ending Balance, Shares at Dec. 31, 2020			50.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(81.3)				(81.3)		(81.3)
Other comprehensive income	37.5					37.5	37.5
Shares issued under employee plans	0.0		$ 0.0	0.0
Shares issued under employee plans, Shares			0.2
Shares purchased under employee plans and other	(2.0)			(2.0)			(2.0)
Stock-based compensation	4.3			4.3			4.3
Equity-based award modification	(10.2)			(10.2)			(10.2)
Dividends on preferred stock	(7.6)			(7.6)			(7.6)
Ending Balance, Equity (Deficit) at Sep. 07, 2021	(250.4)	$ 129.4	$ 0.5	2,654.8	(2,912.9)	(122.2)	(250.4)	0.0
Ending Balance, Shares at Sep. 07, 2021		3.1
Ending Balance, Shares at Sep. 07, 2021			50.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(27.2)
Other comprehensive income	1.2
Ending Balance, Equity (Deficit) at Dec. 31, 2021	1,690.1	$ 0.0	$ 0.0	1,716.1	(27.2)	1.2	1,690.1	0.0
Ending Balance, Shares at Dec. 31, 2021		0.0
Ending Balance, Shares at Dec. 31, 2021			0.0
Beginning Balance, Equity (Deficit) at Sep. 08, 2021	0.0	$ 0.0	$ 0.0	0.0	0.0	0.0	0.0	0.0
Beginning Balance, Shares at Sep. 08, 2021		0.0
Beginning Balance, Shares at Sep. 08, 2021			0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(27.2)				(27.2)		(27.2)
Other comprehensive income	1.2					1.2	1.2
Capital contributions by Red Fiber Parent LLC	1,716.1			1,716.1			1,716.1
Ending Balance, Equity (Deficit) at Dec. 31, 2021	1,690.1	$ 0.0	$ 0.0	1,716.1	(27.2)	1.2	1,690.1	0.0
Ending Balance, Shares at Dec. 31, 2021		0.0
Ending Balance, Shares at Dec. 31, 2021			0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(130.9)				(130.9)		(130.9)
Other comprehensive income	18.3					18.3	18.3
Partner contribution to Digital Access Ohio	0.8							0.8
Ending Balance, Equity (Deficit) at Dec. 31, 2022	$ 1,578.3	$ 0.0	$ 0.0	$ 1,716.1	$ (158.1)	$ 19.5	$ 1,577.5	$ 0.8
Ending Balance, Shares at Dec. 31, 2022		0.0
Ending Balance, Shares at Dec. 31, 2022			0.0