Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment	$ 309.6	$ 295.5
Accumulated depreciation and amortization	(132.5)	(115.6)
Property and equipment, net	177.1	179.9
Land
Property, Plant and Equipment [Line Items]
Property and equipment	11.9	11.9
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property and equipment	71.1	65.8
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	6.7	5.4
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment	208.9	203.1
Furniture, fixtures and other equipment
Property, Plant and Equipment [Line Items]
Property and equipment	$ 11.0	$ 9.3