Derivative Financial Instruments (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended
Jul. 31, 2014	Jul. 31, 2013
Gains and losses recognized in cost of products sold on derivatives not designated as qualified hedging instruments
Total gains (losses) recognized in cost of products sold	$ (21.7)	$ (0.8)
Commodity contracts [Member]
Gains and losses recognized in cost of products sold on derivatives not designated as qualified hedging instruments
Total gains (losses) recognized in cost of products sold	(21.1)	(1.9)
Foreign currency exchange contracts [Member]
Gains and losses recognized in cost of products sold on derivatives not designated as qualified hedging instruments
Total gains (losses) recognized in cost of products sold	$ (0.6)	$ 1.1

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959

Name:	us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration