Goodwill - Schedule of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 3,613.4	$ 2,361.4
Goodwill, ending balance	3,817.3	3,613.4
Optimal Blue Holdco, LLC
Goodwill [Roll Forward]
Acquisitions	(8.1)	(1,206.0)
Other Acquisitions
Goodwill [Roll Forward]
Acquisitions		(46.0)
2021 acquisitions
Goodwill [Roll Forward]
Acquisitions	(212.0)
Operating Segments | Software Solutions
Goodwill [Roll Forward]
Goodwill, beginning balance	3,415.8	2,189.3
Goodwill, ending balance	3,602.4	3,415.8
Operating Segments | Data and Analytics
Goodwill [Roll Forward]
Goodwill, beginning balance	197.6	172.1
Goodwill, ending balance	214.9	197.6
Operating Segments | Optimal Blue Holdco, LLC | Software Solutions
Goodwill [Roll Forward]
Acquisitions	(8.1)	(1,206.0)
Operating Segments | Other Acquisitions | Software Solutions
Goodwill [Roll Forward]
Acquisitions		(20.5)
Operating Segments | Other Acquisitions | Data and Analytics
Goodwill [Roll Forward]
Acquisitions		$ (25.5)
Operating Segments | 2021 acquisitions | Software Solutions
Goodwill [Roll Forward]
Acquisitions	(194.7)
Operating Segments | 2021 acquisitions | Data and Analytics
Goodwill [Roll Forward]
Acquisitions	$ (17.3)