Acquisition - Final Purchase Price Allocation (Details) - USD ($) $ in Millions	Feb. 01, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill		$ 2,553.0	$ 2,462.8	$ 2,479.6
Total purchase price	$ 88.0
Scalar
Business Acquisition [Line Items]
Net assets acquired	5.7
Identified intangible assets	20.3
Goodwill	62.0
Total purchase price	88.0
Deferred tax liability	$ 7.0