Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue
Services	$ 1,006.1	$ 978.7	$ 933.0
Products	282.4	207.1	234.8
Total revenue	1,288.5	1,185.8	1,167.8
Costs and expenses
Cost of services, excluding items below	532.1	506.4	472.5
Cost of products sold, excluding items below	229.2	172.5	198.1
Selling, general and administrative	240.9	218.7	219.1
Depreciation and amortization	193.0	182.2	141.6
Restructuring and severance related charges	32.7	11.9	6.0
Transaction and integration cost	18.5	0.0	1.4
Other	4.0	1.1	1.1
Total operating costs and expenses	1,250.4	1,092.8	1,039.8
Operating (loss) income	38.1	93.0	128.0
Interest expense	85.2	75.7	103.1
Loss on extinguishment of debt, net	3.2	19.0	20.9
Gain on sale of CyrusOne investment	(117.7)	(157.0)	(449.2)
Other (income) expense, net	1.4	(7.6)	2.6
Income from continuing operations before income taxes	66.0	162.9	450.6
Income tax expense (benefit)	30.9	61.1	159.8
Income from continuing operations	35.1	101.8	290.8
Income (loss) from discontinued operations, net of tax	0.0	0.3	62.9
Net income	35.1	102.1	353.7
Preferred stock dividends	10.4	10.4	10.4
Net income applicable to common shareowners	$ 24.7	$ 91.7	$ 343.3
Basic earnings per common share from continuing operations		$ 2.17
Basic earnings per common share from discontinued operations		0.01
Basic net earnings per common share	$ 0.59	2.18	$ 8.19
Diluted earnings per common share from continuing operations		2.17
Diluted earnings per common share from discontinued operations		0.01
Diluted net earnings per common share	$ 0.58	$ 2.18	$ 8.17
Weighted-average common shares outstanding - basic	42.2	42.0	41.9
Weighted-average common shares outstanding - diluted	42.4	42.1	42.0
Continuing Operations [Member]
Costs and expenses
Depreciation and amortization	$ 193.0	$ 182.2	$ 141.6
Income tax expense (benefit)	30.9	61.1	159.8
Income from continuing operations	35.1	101.8	290.8
Preferred stock dividends	$ 10.4	$ 10.4	$ 10.4
Basic earnings per common share from continuing operations	$ 0.59		$ 6.69
Diluted earnings per common share from continuing operations	$ 0.58	$ 2.17	$ 6.68
Weighted-average common shares outstanding - basic	42.2	42.0	41.9
Weighted-average common shares outstanding - diluted	42.4	42.1	42.0
Discontinued Operations [Member]
Revenue
Total revenue	$ 0.0	$ 0.0	$ 4.4
Costs and expenses
Selling, general and administrative	0.0	0.0	2.2
Depreciation and amortization	0.0	0.0	28.6
Total operating costs and expenses	0.0	0.0	39.2
Operating (loss) income	0.0	0.0	(34.8)
Other (income) expense, net	0.0	(0.3)	(2.3)
Income tax expense (benefit)	0.0	0.0	34.8
Income (loss) from discontinued operations, net of tax	0.0	0.3	62.9
Preferred stock dividends	$ 0.0	$ 0.0	$ 0.0
Basic earnings per common share from discontinued operations	$ 0.00		$ 1.50
Diluted earnings per common share from discontinued operations	$ 0.00	$ 0.01	$ 1.49
Weighted-average common shares outstanding - basic	0.0	42.0	41.9
Weighted-average common shares outstanding - diluted	0.0	42.1	42.0