Restructuring and Severance - Summary of Restructuring Activity by Business Segment (Details) - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2021	Sep. 07, 2021	Dec. 31, 2023	Dec. 31, 2022
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 0.1	$ 4.5	$ 0.0	$ 0.2
Charges	0.6	1.2	13.8	2.0
Utilizations	(0.5)	(5.6)	(3.3)	(2.2)
Ending Balance	0.2	0.1	10.5	0.0
Operating Segments [Member] | Network [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0.1	4.4	0.0	0.1
Charges	0.0	(0.5)	10.3	0.0
Utilizations	0.0	(3.8)	(0.6)	(0.1)
Ending Balance	0.1	0.1	9.7	0.0
Operating Segments [Member] | IT Services and Hardware [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0.0	0.0	0.0	0.1
Charges	0.6	1.7	3.0	2.0
Utilizations	(0.5)	(1.7)	(2.7)	(2.1)
Ending Balance	0.1	0.0	0.3	0.0
Corporate [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0.0	0.1	0.0	0.0
Charges	0.0	0.0	0.5	0.0
Utilizations	0.0	(0.1)	0.0	0.0
Ending Balance	$ 0.0	$ 0.0	$ 0.5	$ 0.0