Revenue - Schedule of Revenues Disaggregation by Contract Type (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
Disaggregation Of Revenue [Line Items]
Revenues	$ 554.4	$ 1,138.7	$ 1,817.3	$ 1,796.0
Transferred at Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Revenues	67.4	105.9	201.7	194.5
Transferred over Time [Member]
Disaggregation Of Revenue [Line Items]
Revenues	487.0	1,032.8	1,615.6	1,601.5
Intersegment Eliminations [Member]
Disaggregation Of Revenue [Line Items]
Revenues	(8.7)	(17.9)	(24.3)	(26.2)
Network [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenues	303.8	664.2	1,002.9	994.3
Network [Member] | Operating Segments [Member] | Transferred at Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Revenues	8.0	15.8	26.3	27.3
Network [Member] | Operating Segments [Member] | Transferred over Time [Member]
Disaggregation Of Revenue [Line Items]
Revenues	289.3	635.3	960.2	947.7
Network [Member] | Intersegment Eliminations [Member]
Disaggregation Of Revenue [Line Items]
Revenues	6.5	13.1	16.4	19.3
IT Services and Hardware [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenues	259.3	492.4	838.7	827.9
IT Services and Hardware [Member] | Operating Segments [Member] | Transferred at Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Revenues	59.4	90.1	175.4	167.2
IT Services and Hardware [Member] | Operating Segments [Member] | Transferred over Time [Member]
Disaggregation Of Revenue [Line Items]
Revenues	197.7	397.5	655.4	653.8
IT Services and Hardware [Member] | Intersegment Eliminations [Member]
Disaggregation Of Revenue [Line Items]
Revenues	$ 2.2	$ 4.8	$ 7.9	$ 6.9