Condensed Statements of Consolidated Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2017	Jan. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 134.6	$ 185.3	$ 481.9	$ 497.7
Other comprehensive income (loss):
Foreign currency translation adjustments	9.0	(21.5)	(17.2)	(44.4)
Cash flow hedging derivative activity, net of tax	0.1	0.1	0.3	0.3
Pension and other postretirement benefit plans activity, net of tax	1.3	3.0	19.3	7.1
Available-for-sale securities activity, net of tax	(0.7)	0.4	(0.4)	0.0
Total Other Comprehensive Income (Loss)	9.7	(18.0)	2.0	(37.0)
Comprehensive Income	$ 144.3	$ 167.3	$ 483.9	$ 460.7