Goodwill and Other Intangible Assets - Balances of Goodwill by Reporting Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Gross book value		$ 446.4
Accumulated impairment charges		(40.6)
Goodwill, beginning balance	$ 405.8
Foreign exchange and other adjustments	0.0
Goodwill, ending balance	405.8
Capital Markets - Software Solutions
Goodwill [Line Items]
Gross book value		100.1
Accumulated impairment charges		0.0
Goodwill, beginning balance	100.1
Foreign exchange and other adjustments	0.0
Goodwill, ending balance	100.1
Capital Markets - Compliance and Communications Management
Goodwill [Line Items]
Gross book value		252.7
Accumulated impairment charges		0.0
Goodwill, beginning balance	252.7
Foreign exchange and other adjustments	0.0
Goodwill, ending balance	252.7
Investment Companies - Software Solutions
Goodwill [Line Items]
Gross book value		53.0
Accumulated impairment charges		0.0
Goodwill, beginning balance	53.0
Foreign exchange and other adjustments	0.0
Goodwill, ending balance	53.0
Investment Companies - Compliance and Communications Management
Goodwill [Line Items]
Gross book value		40.6
Accumulated impairment charges		$ (40.6)
Goodwill, beginning balance	0.0
Foreign exchange and other adjustments	0.0
Goodwill, ending balance	$ 0.0