Goodwill and Other Intangible Assets - Schedule of Goodwill by Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Goodwill [Roll Forward]
Beginning balance	$ 4,413.4	$ 4,342.7
Foreign currency translation	(11.1)	14.7
Ending balance	4,620.4	4,413.4
Immaterial acquisitions
Goodwill [Roll Forward]
Acquisition activity		56.0
Mission Cloud Services Inc.
Goodwill [Roll Forward]
Acquisition activity	218.1
Corporate
Goodwill [Roll Forward]
Beginning balance	2,153.1	2,133.4
Foreign currency translation	0.0	0.0
Ending balance	2,370.8	2,153.1
Accumulated impairment losses	1,571.0
Corporate | Immaterial acquisitions
Goodwill [Roll Forward]
Acquisition activity		19.7
Corporate | Mission Cloud Services Inc.
Goodwill [Roll Forward]
Acquisition activity	217.7
Small Business
Goodwill [Roll Forward]
Beginning balance	230.2	230.2
Foreign currency translation	0.0	0.0
Ending balance	230.2	230.2
Small Business | Immaterial acquisitions
Goodwill [Roll Forward]
Acquisition activity		0.0
Small Business | Mission Cloud Services Inc.
Goodwill [Roll Forward]
Acquisition activity	0.0
Public
Goodwill [Roll Forward]
Beginning balance	1,695.1	1,658.8
Foreign currency translation	0.0	0.0
Ending balance	1,695.5	1,695.1
Accumulated impairment losses	354.0
Public | Immaterial acquisitions
Goodwill [Roll Forward]
Acquisition activity		36.3
Public | Mission Cloud Services Inc.
Goodwill [Roll Forward]
Acquisition activity	0.4
Other
Goodwill [Roll Forward]
Beginning balance	335.0	320.3
Foreign currency translation	(11.1)	14.7
Ending balance	323.9	335.0
Accumulated impairment losses	28.0
Other | Immaterial acquisitions
Goodwill [Roll Forward]
Acquisition activity		$ 0.0
Other | Mission Cloud Services Inc.
Goodwill [Roll Forward]
Acquisition activity	$ 0.0