Other Non-Current Assets (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Property records database	$ 60.2		$ 60.1
Contract assets, net	47.3		37.8
Right-of-use assets(1)	24.8		26.4
Deferred compensation plan related assets	16.4		15.2
Prepaid expenses	3.6		8.1
Unbilled receivables, net	2.1		3.5
Other	8.4		7.7
Other non-current assets	162.8		$ 158.8
Non-cash additions for right-of-use assets, net of modifications	$ 4.5	$ 1.8