Derivative Financial Instruments (Details 3) - USD ($) $ in Millions	3 Months Ended
Jul. 31, 2015	Jul. 31, 2014
Unallocated Derivative Gains (Losses)
Net losses on mark-to-market valuation of unallocated derivative positions	$ (10.7)	$ (21.7)
Net losses on derivative positions reclassified to segment operating profit	0.7	0.3
Unallocated derivative losses	$ (10.0)	$ (21.4)

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=35706170&loc=SL5624171-113959

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