Condensed Consolidated Statements of Operations - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Income Statement [Abstract]
Revenue	$ 274.8	$ 272.8	$ 551.2	$ 544.4
Costs and expenses
Cost of services and products, excluding items below	120.8	132.1	242.9	265.6
Selling, general and administrative, excluding items below	55.0	62.9	110.0	126.1
Depreciation and amortization	87.3	80.3	171.9	157.7
Restructuring and severance related charges	(0.2)	(0.3)	3.5	(0.1)
Transaction and integration costs	0.5	0.0	0.8	0.1
Total operating costs and expenses	263.4	275.0	529.1	549.4
Operating income (loss)	11.4	(2.2)	22.1	(5.0)
Interest expense	33.2	45.3	66.3	86.9
Other components of pension and postretirement benefit plans benefit	(1.2)	(1.0)	(2.6)	(1.5)
Other income, net	(3.1)	(6.5)	(10.2)	(36.5)
Loss from continuing operations before income taxes	(17.5)	(40.0)	(31.4)	(53.9)
Income tax expense (benefit)	0.6	(2.6)	1.1	31.2
Loss from continuing operations	(18.1)	(37.4)	(32.5)	(85.1)
Income (loss) from discontinued operations (net of tax)	0.0	3.1	(13.9)	9.9
Net loss	$ (18.1)	$ (34.3)	$ (46.4)	$ (75.2)