Restructuring and Severance - Summary of activity in the restructuring and severance liability (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 10.2
Charges	0.2	$ 0.0
Utilizations	(6.4)
Ending Balance	4.0
Corporate [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0.5
Charges	0.0
Utilizations	(0.1)
Ending Balance	0.4
Network [Member] | Operating Segments [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	9.7
Charges	0.2
Utilizations	(6.3)
Ending Balance	$ 3.6