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		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Restructuring Cost And Reserve [Line Items]
Employee Terminations	$ 0.1	$ 2.7	$ 1.7	$ 2.9
Other Restructuring Charges	0.1		0.1	0.6
Other Charges		0.1	0.2	0.1
Total	0.2	2.8	2.0	3.6
Capital Markets - Software Solutions
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.2	0.1	1.0	0.1
Other Restructuring Charges	0.0		0.0	0.0
Other Charges		0.0	0.0	0.0
Total	0.2	0.1	1.0	0.1
Capital Markets - Compliance and Communications Management
Restructuring Cost And Reserve [Line Items]
Employee Terminations		0.5	0.3	0.5
Other Restructuring Charges			0.0	0.0
Other Charges		0.1	0.1	0.1
Total		0.6	0.4	0.6
Investment Companies - Software Solutions
Restructuring Cost And Reserve [Line Items]
Employee Terminations		0.1	0.1	0.1
Other Restructuring Charges			0.0	0.0
Other Charges		0.0	0.0	0.0
Total		0.1	0.1	0.1
Investment Companies - Compliance and Communications Management
Restructuring Cost And Reserve [Line Items]
Employee Terminations	(0.3)	1.9	0.1	2.0
Other Restructuring Charges	0.1		0.1	0.6
Other Charges		0.0	0.0	0.0
Total	(0.2)	1.9	0.2	2.6
Corporate
Restructuring Cost And Reserve [Line Items]
Employee Terminations	0.2	0.1	0.2	0.2
Other Restructuring Charges	0.0		0.0	0.0
Other Charges		0.0	0.1	0.0
Total	$ 0.2	$ 0.1	$ 0.3	$ 0.2