Fair Value Measurements (Details) $ in Millions	Dec. 31, 2020 USD ($) contract	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Cash Flow Hedging
Fair value of assets and liabilities measured on recurring basis
Number of forward contracts | contract	2
Fair value measurements recurring basis
Fair value of assets and liabilities measured on recurring basis
Short-term investments	$ 36.1		$ 17.4
Forward contracts	(2.7)		(1.3)
Contingent consideration			(75.0)
Total liability			(58.9)
Total asset	33.4
Fair value measurements recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair value of assets and liabilities measured on recurring basis
Short-term investments	36.1		17.4
Forward contracts	0.0		0.0
Contingent consideration			0.0
Total asset	36.1		17.4
Fair value measurements recurring basis | Significant Observable Inputs (Level 2)
Fair value of assets and liabilities measured on recurring basis
Short-term investments	0.0		0.0
Forward contracts	(2.7)		(1.3)
Contingent consideration			0.0
Total liability	(2.7)		(1.3)
Fair value measurements recurring basis | Significant Unobservable Inputs (Level 3)
Fair value of assets and liabilities measured on recurring basis
Short-term investments	0.0		0.0
Forward contracts	0.0		0.0
Contingent consideration			(75.0)
Total liability	$ 0.0		$ (75.0)
SSI Controls Technologies
Fair value of assets and liabilities measured on recurring basis
Contingent consideration		$ (75.0)