Derivative Instruments and Hedging Activities (Derivatives by Balance Sheet Location) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Mar. 31, 2019
Designated as Hedging Instrument | Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	$ 1.6	$ 1.5
Designated as Hedging Instrument | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	0.7	0.6
Designated as Hedging Instrument | Other Non-Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	107.0	63.6
Designated as Hedging Instrument | Forward exchange contracts | Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	1.4	1.5
Designated as Hedging Instrument | Forward exchange contracts | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	0.7	0.6
Designated as Hedging Instrument | Forward exchange contracts | Other Non-Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	0.0	0.0
Designated as Hedging Instrument | Interest rate swap agreements | Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	0.0	0.0
Designated as Hedging Instrument | Interest rate swap agreements | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	0.0	0.0
Designated as Hedging Instrument | Interest rate swap agreements | Other Non-Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	107.0	$ 63.6
Not Designated as Hedging Instrument | Forward exchange contracts | Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	0.2
Not Designated as Hedging Instrument | Forward exchange contracts | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	0.0
Not Designated as Hedging Instrument | Forward exchange contracts | Other Non-Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	$ 0.0