Derivative Financial Instruments (Details 2) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2016	Jan. 31, 2015
Gains and losses recognized in cost of products sold on derivatives not designated as qualified hedging instruments
Total (losses) gains recognized in cost of products sold	$ (12.9)	$ (2.2)	$ (31.2)	$ (20.2)
Commodity contracts [Member]
Gains and losses recognized in cost of products sold on derivatives not designated as qualified hedging instruments
Total (losses) gains recognized in cost of products sold	(23.3)	(13.9)	(50.2)	(34.3)
Foreign currency exchange contracts [Member]
Gains and losses recognized in cost of products sold on derivatives not designated as qualified hedging instruments
Total (losses) gains recognized in cost of products sold	$ 10.4	$ 11.7	$ 19.0	$ 14.1