Condensed Consolidated Statements of Operations - USD ($) $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 07, 2021	Sep. 30, 2020	Sep. 07, 2021	Sep. 30, 2020
Income Statement [Abstract]
Revenue	$ 111.4	$ 314.6	$ 389.5	$ 1,138.7	$ 1,149.5
Costs and expenses
Cost of services and products, excluding items below	60.5	174.6	203.9	619.5	591.0
Selling, general and administrative, excluding items below	22.1	74.2	86.0	243.4	255.3
Depreciation and amortization	30.2	52.1	71.9	194.9	220.8
Restructuring and severance related charges	0.0	0.3	0.8	1.2	16.4
Transaction and integration costs	0.0	51.5	2.2	54.8	33.8
Gain on sale of assets, net	0.0	(2.8)	0.0	(2.8)	0.0
Total operating costs and expenses	112.8	349.9	364.8	1,111.0	1,117.3
Operating (loss) income	(1.4)	(35.3)	24.7	27.7	32.2
Interest expense	6.4	23.2	33.4	89.1	100.6
Other components of pension and postretirement benefit plans (benefit) expense	(1.1)	2.1	2.6	6.4	9.0
Loss on extinguishment of debt	0.0	10.7	0.0	10.7	0.0
Other (income) expense, net	(0.3)	19.7	(0.2)	19.7	(1.2)
Loss before income taxes	(6.4)	(91.0)	(11.1)	(98.2)	(76.2)
Income tax benefit	(1.4)	(17.3)	(2.9)	(16.9)	(26.2)
Net loss	(5.0)	(73.7)	(8.2)	(81.3)	(50.0)
Preferred stock dividends	0.0	2.4	2.6	7.6	7.8
Net loss applicable to common shareowners	$ (5.0)	$ (76.1)	$ (10.8)	$ (88.9)	$ (57.8)