Business Segment Information - Selected Financial Data for the Company's Business Segment Information (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Revenue		$ 380.0	$ 379.6
Operating (loss) income		(20.2)	10.1
Expenditures for long-lived assets	[1]	50.9	56.5
Depreciation and amortization		74.2	79.4
Assets		2,599.6		$ 2,653.8
Operating Segments [Member] | Entertainment and Communications [Member]
Segment Reporting Information [Line Items]
Revenue		243.8	250.3
Operating (loss) income		12.1	24.5
Expenditures for long-lived assets	[1]	44.4	51.1
Depreciation and amortization		63.9	62.7
Assets		1,822.5		1,840.0
Operating Segments [Member] | IT Services and Hardware [Member]
Segment Reporting Information [Line Items]
Revenue		142.3	136.3
Operating (loss) income		1.7	(6.8)
Expenditures for long-lived assets	[1]	6.5	5.4
Depreciation and amortization		10.3	16.7
Assets		464.5		500.7
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Revenue		(6.1)	(7.0)
Intersegment Elimination [Member] | Entertainment and Communications [Member]
Segment Reporting Information [Line Items]
Revenue		4.9	6.0
Intersegment Elimination [Member] | IT Services and Hardware [Member]
Segment Reporting Information [Line Items]
Revenue		1.2	1.0
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating (loss) income		(34.0)	(7.6)
Corporate and Elimination [Member]
Segment Reporting Information [Line Items]
Assets		312.6		$ 313.1
Sales [Member] | Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Revenue		$ 6.1	$ 7.0

[1] Includes cost of acquisitions