Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		12 Months Ended
		Apr. 30, 2025	Apr. 30, 2024	Apr. 30, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance		$ 7,693.9	$ 7,290.8	$ 8,140.1
Balance		6,082.6	7,693.9	7,290.8
Foreign Currency Translation Adjustment [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance		(39.2)	(34.3)	(21.1)
Reclassification adjustments		0.0	0.0	0.0
Current period credit (charge)		(2.5)	(4.9)	(13.2)
Income tax benefit (expense)		0.0	0.0	0.0
Balance		(41.7)	(39.2)	(34.3)
Net Gains (Losses) on Cash Flow Hedging Derivatives [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	[1]	(143.1)	(153.6)	(163.9)
Reclassification adjustments	[1]	69.7	13.6	13.5
Current period credit (charge)	[1]	0.0	0.0	0.0
Income tax benefit (expense)	[1]	(16.7)	(3.1)	(3.2)
Balance	[1]	(90.1)	(143.1)	(153.6)
Pension and Other Postretirement Liabilities [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	[2]	(53.4)	(52.7)	(54.2)
Reclassification adjustments	[2]	1.8	0.3	10.3
Current period credit (charge)	[2]	(1.3)	(1.3)	(7.9)
Income tax benefit (expense)	[2]	(0.3)	0.3	(0.9)
Balance	[2]	(53.2)	(53.4)	(52.7)
Unrealized Gain (Loss) on Available-for-Sale Securities [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance		1.1	1.4	1.8
Reclassification adjustments		0.0	0.0	0.0
Current period credit (charge)		(0.7)	(0.4)	(0.6)
Income tax benefit (expense)		0.1	0.1	0.2
Balance		0.5	1.1	1.4
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance		(234.6)	(239.2)	(237.4)
Reclassification adjustments		71.5	13.9	23.8
Current period credit (charge)		(4.5)	(6.6)	(21.7)
Income tax benefit (expense)		(16.9)	(2.7)	(3.9)
Balance		$ (184.5)	$ (234.6)	$ (239.2)

[1] The reclassification from accumulated other comprehensive income (loss) is primarily composed of deferred gains (losses) related to terminated interest rate contracts which were reclassified to interest expense – net. In addition, a portion of the reclassification in 2025 was reclassified to other debt gains (charges) – net resulting from the extinguishment of debt from the tender offers. For additional information, see Note 10: Derivative Financial Instruments and Note 8: Debt and Financing Arrangements.

[2] The reclassification from accumulated other comprehensive income (loss) to other income (expense) – net is composed of settlement and curtailment activity and amortization of net losses and prior service costs. For additional information, see Note 9: Pensions and Other Postretirement Benefits.