Segment Information - Reconciliation of Operating Profit (Loss) from Segments to Consolidated (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Segment income	$ 157.1	$ 100.7
Other expense	(0.4)	(1.2)
Income from continuing operations before income taxes	151.6	92.6
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Segment income	164.4	111.5
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Deal related costs and expenses	(0.7)	(0.4)
Restructuring and other	(1.5)	(2.4)
Intangible amortization	(7.1)	(7.6)
COVID-19 related costs and expenses	(0.2)	(0.9)
Legal Accrual Adjustments	2.4
Net interest expense	(5.1)	(6.9)
Other expense	$ (0.6)	$ (0.7)