Revenues - Disaggregation of Revenues by Source (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation Of Revenue [Line Items]
Disaggregation of revenue	$ 1,233.4	$ 1,173.6
Software-enabled Services [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of revenue	1,043.4	989.5
Maintenance and Term Licenses [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of revenue	163.2	159.8
Professional Services [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of revenue	23.5	20.0
Perpetual Licenses [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of revenue	$ 3.3	$ 4.3