Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Revenues	$ 312.6	$ 299.1	$ 896.4	$ 877.1
Software and hosting solutions
Disaggregation of Revenue [Line Items]
Revenues	231.6	226.2	672.9	666.5
Professional services
Disaggregation of Revenue [Line Items]
Revenues	32.4	33.2	91.6	98.0
Data solutions
Disaggregation of Revenue [Line Items]
Revenues	44.1	33.0	119.8	94.6
Other
Disaggregation of Revenue [Line Items]
Revenues	4.5	6.7	12.1	18.0
Reportable Legal Entities | Software Services
Disaggregation of Revenue [Line Items]
Revenues	194.2	202.9	574.2	615.4
Reportable Legal Entities | Software Services | Software and hosting solutions
Disaggregation of Revenue [Line Items]
Revenues	174.4	182.4	517.9	546.9
Reportable Legal Entities | Software Services | Professional services
Disaggregation of Revenue [Line Items]
Revenues	19.8	20.5	56.3	63.4
Reportable Legal Entities | Software Services | Data solutions
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Reportable Legal Entities | Software Services | Other
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	5.1
Reportable Legal Entities | Origination Software
Disaggregation of Revenue [Line Items]
Revenues	65.3	54.4	175.1	140.8
Reportable Legal Entities | Origination Software | Software and hosting solutions
Disaggregation of Revenue [Line Items]
Revenues	48.6	35.7	129.5	95.8
Reportable Legal Entities | Origination Software | Professional services
Disaggregation of Revenue [Line Items]
Revenues	12.6	12.6	35.1	34.0
Reportable Legal Entities | Origination Software | Data solutions
Disaggregation of Revenue [Line Items]
Revenues	0.2	0.0	0.2	0.0
Reportable Legal Entities | Origination Software | Other
Disaggregation of Revenue [Line Items]
Revenues	3.9	6.1	10.3	11.0
Operating Segments | Software Solutions
Disaggregation of Revenue [Line Items]
Revenues	259.5	257.3	749.3	756.2
Operating Segments | Software Solutions | Software and hosting solutions
Disaggregation of Revenue [Line Items]
Revenues	223.0	218.1	647.4	642.7
Operating Segments | Software Solutions | Professional services
Disaggregation of Revenue [Line Items]
Revenues	32.4	33.1	91.4	97.4
Operating Segments | Software Solutions | Data solutions
Disaggregation of Revenue [Line Items]
Revenues	0.2	0.0	0.2	0.0
Operating Segments | Software Solutions | Other
Disaggregation of Revenue [Line Items]
Revenues	3.9	6.1	10.3	16.1
Operating Segments | Data and Analytics
Disaggregation of Revenue [Line Items]
Revenues	53.1	41.9	147.4	121.3
Operating Segments | Data and Analytics | Software and hosting solutions
Disaggregation of Revenue [Line Items]
Revenues	8.6	8.1	25.5	23.8
Operating Segments | Data and Analytics | Professional services
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.2	0.5	1.0
Operating Segments | Data and Analytics | Data solutions
Disaggregation of Revenue [Line Items]
Revenues	43.9	33.0	119.6	94.6
Operating Segments | Data and Analytics | Other
Disaggregation of Revenue [Line Items]
Revenues	0.6	0.6	1.8	1.9
Corporate and Other
Disaggregation of Revenue [Line Items]
Revenues	0.0	(0.1)	(0.3)	(0.4)
Corporate and Other | Software and hosting solutions
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Corporate and Other | Professional services
Disaggregation of Revenue [Line Items]
Revenues	0.0	(0.1)	(0.3)	(0.4)
Corporate and Other | Data solutions
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Corporate and Other | Other
Disaggregation of Revenue [Line Items]
Revenues	$ 0.0	$ 0.0	$ 0.0	$ 0.0