Goodwill and Other Intangibles (Details) - Schedule of activity in goodwill (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
Feb. 28, 2015	Feb. 28, 2014	May 31, 2014
Goodwill [Roll Forward]
Gross beginning balance	$ 178.7us-gaap_GoodwillGross	$ 178.7us-gaap_GoodwillGross	$ 178.7us-gaap_GoodwillGross
Accumulated impairment	(34.2)	(20.8)	(20.8)
Beginning balance	144.5us-gaap_Goodwill	157.9us-gaap_Goodwill	157.9us-gaap_Goodwill
Impairment charge	0us-gaap_GoodwillImpairmentLoss	(13.4)us-gaap_GoodwillImpairmentLoss	(13.4)us-gaap_GoodwillImpairmentLoss
Foreign currency translation	(0.1)us-gaap_GoodwillTranslationAdjustments	0us-gaap_GoodwillTranslationAdjustments	0us-gaap_GoodwillTranslationAdjustments
Gross ending balance	178.6us-gaap_GoodwillGross	178.7us-gaap_GoodwillGross	178.7us-gaap_GoodwillGross
Accumulated impairment	(34.2)	(34.2)	(34.2)
Ending balance	$ 144.4us-gaap_Goodwill	$ 144.5us-gaap_Goodwill	$ 144.5us-gaap_Goodwill

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

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-Section 45

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-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

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- Definition

Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

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Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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- Definition

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-Publisher FASB

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Amount of increase (decrease) from foreign currency translation adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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