Derivative Financial Instruments (Details 2) - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019
Gains and losses recognized in cost of products sold on derivatives not designated as qualified hedging instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 92.6	$ (29.1)	$ (95.6)
Commodity price derivatives
Gains and losses recognized in cost of products sold on derivatives not designated as qualified hedging instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	101.4	(31.4)	(98.6)
Foreign currency exchange derivatives
Gains and losses recognized in cost of products sold on derivatives not designated as qualified hedging instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (8.8)	$ 2.3	$ 3.0