Condensed Statements of Consolidated Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Jul. 31, 2020	Jul. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 237.0	$ 154.6
Other comprehensive income (loss):
Foreign currency translation adjustments	12.9	4.5
Cash flow hedging derivative activity, net of tax	2.6	(40.8)
Pension and other postretirement benefit plans activity, net of tax	1.7	1.1
Available-for-sale securities activity, net of tax	0.9	0.3
Total Other Comprehensive Income (Loss)	18.1	(34.9)
Comprehensive Income	$ 255.1	$ 119.7