Goodwill - Schedule of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 2,306.8	$ 2,303.8
Activity		3.0
Acquisitions	22.9
Goodwill, ending balance	2,329.7	2,306.8
Goodwill deductible for tax purposes	19.7
Goodwill not deductible for tax purposes	3.2
Operating Segments | Software Solutions
Goodwill [Roll Forward]
Goodwill, beginning balance	2,134.7	2,131.7
Activity		3.0
Acquisitions	22.9
Goodwill, ending balance	2,157.6	2,134.7
Operating Segments | Data and Analytics
Goodwill [Roll Forward]
Goodwill, beginning balance	172.1	172.1
Activity		0.0
Acquisitions	0.0
Goodwill, ending balance	172.1	172.1
Corporate and Other
Goodwill [Roll Forward]
Goodwill, beginning balance	0.0	0.0
Activity		0.0
Acquisitions	0.0
Goodwill, ending balance	$ 0.0	$ 0.0