v3.26.1
Goodwill - Balances of Goodwill by Reporting Segment (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Goodwill [Line Items]    
Gross book value   $ 446.4
Accumulated impairment charges   (40.6)
Goodwill, beginning balance $ 405.8  
Foreign exchange adjustments (0.2)  
Goodwill, ending balance 405.6  
Capital Markets - Software Solutions    
Goodwill [Line Items]    
Gross book value   100.0
Accumulated impairment charges   0.0
Goodwill, beginning balance 100.0  
Foreign exchange adjustments (0.1)  
Goodwill, ending balance 99.9  
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 adjustments (0.0)  
Goodwill, ending balance 252.7  
Investment Companies - Software Solutions    
Goodwill [Line Items]    
Gross book value   53.1
Accumulated impairment charges   0.0
Goodwill, beginning balance 53.1  
Foreign exchange adjustments (0.1)  
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 adjustments 0.0  
Goodwill, ending balance $ 0.0