Restructuring, Impairment and Other Charges - Schedule of Restructuring and Other Charges by Segment Recognized in Results of Operations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Restructuring Cost And Reserve [Line Items]
Employee Terminations	$ 1.6	$ 0.2
Other Restructuring Charges		0.6
Other Charges	0.2
Total	1.8	0.8
Capital Markets - Software Solutions
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.8
Other Charges	0.0
Total	0.8
Capital Markets - Compliance and Communications Management
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.3
Other Charges	0.1
Total	0.4
Investment Companies - Software Solutions
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.1
Other Charges	0.0
Total	0.1
Investment Companies - Compliance and Communications Management
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.4	0.1
Other Restructuring Charges		0.6
Other Charges	0.0
Total	0.4	0.7
Corporate
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.0	0.1
Other Restructuring Charges		0.0
Other Charges	0.1
Total	$ 0.1	$ 0.1