Revenue - Schedule of Revenues Disaggregation by Product and Service Lines (Details) - USD ($) $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 07, 2021	Sep. 30, 2020	Sep. 07, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Revenues	$ 111.4	$ 314.6	$ 389.5	$ 1,138.7	$ 1,149.5
Operating Segments [Member] | Entertainment and Communications [Member]
Disaggregation Of Revenue [Line Items]
Revenues	61.7	180.4	241.0	664.2	724.5
Operating Segments [Member] | Entertainment and Communications [Member] | Data [Member]
Disaggregation Of Revenue [Line Items]
Revenues	31.6	91.7	119.8	334.6	358.8
Operating Segments [Member] | Entertainment and Communications [Member] | Video [Member]
Disaggregation Of Revenue [Line Items]
Revenues	12.2	35.3	48.1	131.8	145.1
Operating Segments [Member] | Entertainment and Communications [Member] | Voice [Member]
Disaggregation Of Revenue [Line Items]
Revenues	15.8	46.8	65.5	177.3	197.6
Operating Segments [Member] | Entertainment and Communications [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenues	2.1	6.6	7.6	20.5	23.0
Operating Segments [Member] | IT Services and Hardware [Member]
Disaggregation Of Revenue [Line Items]
Revenues	52.0	138.7	155.2	492.4	444.5
Operating Segments [Member] | IT Services and Hardware [Member] | Consulting
Disaggregation Of Revenue [Line Items]
Revenues	21.6	56.5	49.4	193.6	138.5
Operating Segments [Member] | IT Services and Hardware [Member] | Cloud
Disaggregation Of Revenue [Line Items]
Revenues	6.6	18.7	21.1	66.4	63.0
Operating Segments [Member] | IT Services and Hardware [Member] | Communications
Disaggregation Of Revenue [Line Items]
Revenues	14.2	40.1	53.9	149.1	160.3
Operating Segments [Member] | IT Services and Hardware [Member] | Infrastructure Solutions
Disaggregation Of Revenue [Line Items]
Revenues	9.6	23.4	30.8	83.3	82.7
Intersegment Eliminations [Member]
Disaggregation Of Revenue [Line Items]
Revenues	(2.3)	(4.5)	(6.7)	(17.9)	(19.5)
Intersegment Eliminations [Member] | Entertainment and Communications [Member]
Disaggregation Of Revenue [Line Items]
Revenues	1.6	3.4	4.9	13.1	14.8
Intersegment Eliminations [Member] | IT Services and Hardware [Member]
Disaggregation Of Revenue [Line Items]
Revenues	$ 0.7	$ 1.1	$ 1.8	$ 4.8	$ 4.7