Derivative Financial Instruments (Details 1) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2015	Oct. 31, 2014
Cash flow hedging derivative instruments gain loss
Change in accumulated other comprehensive loss	$ 0.2	$ (11.6)	$ 0.3	$ (18.5)
Cash Flow Hedging [Member] \| Commodity contracts [Member] \| Cost of Products Sold [Member]
Cash flow hedging derivative instruments gain loss
Gains (losses) reclassified from accumulated other comprehensive loss to earnings (effective portion)	0.0	11.8	0.0	18.8
Cash Flow Hedging [Member] \| Interest rate contract [Member] \| Interest Expense [Member]
Cash flow hedging derivative instruments gain loss
Gains (losses) reclassified from accumulated other comprehensive loss to earnings (effective portion)	$ (0.2)	$ (0.2)	$ (0.3)	$ (0.3)

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and 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 (c)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4D

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624177-113959

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