Derivative Instruments and Hedging Activities (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023
Derivative [Line Items]
Remaining maturity of forward foreign exchange contracts, maximum	19 months
Unrealized gains in AOCI at time of termination	$ 224.6	$ 218.8	$ 49.0	$ 310.5	$ (728.2)	$ (786.0)
Foreign currency cash flow hedge gains estimated to be reclassified into earnings during next 12 months	1.2
Interest rate swap cash flow hedge gain estimated to be reclassified into earnings during next 12 months	23.4
Net Cash Provided by (Used in) Operating Activities	(240.9)	330.3
Net Cash Provided by (Used in) Financing Activities	(199.7)	$ 341.9
Interest rate swaps | Designated as Hedging Instrument
Derivative [Line Items]
US Dollar Amount or Notional Amount	1,920.0			1,920.0
Interest rate swaps | Interest Rate Swap, Fixed Rate Paid 2.915%, Effective Date May 23, 2018 | Designated as Hedging Instrument
Derivative [Line Items]
US Dollar Amount or Notional Amount	$ 300.0			$ 300.0