Revenue - Disaggregated Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue, Net	$ 295.7	$ 249.6
Entertainment and Communications [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	174.2	175.1
IT Services and Hardware [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	127.6	81.0
Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	(6.1)	(6.5)
Intersegment Eliminations [Member] | Entertainment and Communications [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	5.2	5.4
Intersegment Eliminations [Member] | IT Services and Hardware [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	0.9	1.1
Consolidation, Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	0.0	0.0
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	40.1	15.8
Transferred at Point in Time [Member] | Entertainment and Communications [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	4.8	5.1
Transferred at Point in Time [Member] | IT Services and Hardware [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	35.3	10.7
Transferred at Point in Time [Member] | Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	0.0	0.0
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	255.6	233.8
Transferred over Time [Member] | Entertainment and Communications [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	164.2	164.6
Transferred over Time [Member] | IT Services and Hardware [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	91.4	69.2
Transferred over Time [Member] | Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	0.0	0.0
Voice [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	84.9	84.4
Data [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	47.0	51.7
Video [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	39.2	35.9
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	3.1	3.1
Consulting [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	38.1	16.7
Cloud [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	22.6	20.9
Communications [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	40.6	36.5
Infrastructure Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	$ 26.3	$ 6.9