Business Segment Information (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenues		$ 379.6	$ 295.7
Operating income		10.1	24.2
Expenditures for long-lived assets		56.5	32.7
Depreciation and amortization		79.4	51.2
Assets		2,649.3		$ 2,730.2
Entertainment and Communications [Member]
Segment Reporting Information [Line Items]
Revenues		250.3	174.2
Operating income		24.5	28.6
Expenditures for long-lived assets		51.1	27.6
Depreciation and amortization		62.7	40.9
Assets		1,907.4		1,898.8
IT Services and Hardware [Member]
Segment Reporting Information [Line Items]
Revenues		136.3	127.6
Operating income		(6.8)	1.4
Expenditures for long-lived assets		5.4
Depreciation and amortization		16.7	10.2
Assets		460.7		468.1
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Operating income		(7.6)	(5.8)
Depreciation and amortization		0.0	0.1
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Revenues		(7.0)	(6.1)
Intersegment Elimination [Member] | Entertainment and Communications [Member]
Segment Reporting Information [Line Items]
Revenues		6.0	5.2
Intersegment Elimination [Member] | IT Services and Hardware [Member]
Segment Reporting Information [Line Items]
Revenues		1.0	0.9
Intersegment Elimination [Member] | Corporate Segment [Member]
Segment Reporting Information [Line Items]
Assets		281.2		$ 363.3
Sales [Member] | Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Revenues		$ 7.0	6.1
Expenditures for Long-Lived Assets, Including Acquisitions of Businesses [Member]
Segment Reporting Information [Line Items]
Expenditures for long-lived assets	[1]		35.5
Expenditures for Long-Lived Assets, Including Acquisitions of Businesses [Member] | IT Services and Hardware [Member]
Segment Reporting Information [Line Items]
Expenditures for long-lived assets	[1]		$ 7.9

[1] Includes cost of acquisitions