Segment Information - Schedule of Depreciation and Amortization, Assets and Capital Expenditures (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 15.1	$ 14.3	$ 29.2	$ 28.2
Capital expenditures	16.7	19.4	30.0	31.7
Operating Segments
Segment Reporting Information [Line Items]
Depreciation and amortization	15.1	14.3	29.2	28.2
Capital expenditures	15.8	19.2	29.0	31.0
Operating Segments \| Capital Markets - Software Solutions
Segment Reporting Information [Line Items]
Depreciation and amortization	7.7	6.7	14.7	13.2
Capital expenditures	8.5	10.7	14.7	14.4
Operating Segments \| Capital Markets - Compliance and Communications Management
Segment Reporting Information [Line Items]
Depreciation and amortization	1.7	2.0	3.1	4.1
Capital expenditures	2.4	1.9	4.4	3.8
Operating Segments \| Investment Companies - Software Solutions
Segment Reporting Information [Line Items]
Depreciation and amortization	4.7	4.4	9.5	8.6
Capital expenditures	4.3	5.9	8.8	11.0
Operating Segments \| Investment Companies - Compliance and Communications Management
Segment Reporting Information [Line Items]
Depreciation and amortization	1.0	1.2	1.9	2.3
Capital expenditures	0.6	0.7	1.1	1.8
Corporate
Segment Reporting Information [Line Items]
Depreciation and amortization	0.0	0.0	0.0	0.0
Capital expenditures	$ 0.9	$ 0.2	$ 1.0	$ 0.7