Business Acquisitions and Dispositions - Summary of the 2019 Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 1,923.3	$ 1,811.8	$ 1,784.4
2019 Acquisitions
Business Acquisition [Line Items]
Tangible assets acquired		17.9
Intangible assets		33.2
Goodwill		32.5
Net deferred taxes		(4.4)
Other liabilities assumed		(7.9)
Total Estimate of Consideration Transferred, Net of Cash Acquired		$ 71.3