Fair value, after effects of master netting arrangements, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset offset against an obligation to return collateral. Includes assets not subject to a master netting arrangement and not elected to be offset.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=56946850&loc=d3e41678-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section 55
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- References

No definition available.

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- Definition

Nominal or face amount used to calculate payments on the derivative liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Topic 815
-SubTopic 10
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Notional Amount
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- Definition

The number of derivative instruments of a particular group held by the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Derivative Instruments and Hedging Activities (Details) $ in Millions	Feb. 29, 2016 USD ($) item	May. 31, 2015 USD ($)
Derivative Instruments and Hedging Activities
Number of derivative financial instruments \| item	2
Interest rate cap \| Derivatives designated as hedging instruments: \| Cash flow hedges
Derivative Instruments and Hedging Activities
Notional amount under revolving credit agreement	$ 50.0
Interest rate swap \| Derivatives designated as hedging instruments: \| Cash flow hedges
Derivative Instruments and Hedging Activities
Notional amount under revolving credit agreement	$ 50.0
Interest Rate Swap and Cap Agreements \| Derivatives designated as hedging instruments:
Derivative Instruments and Hedging Activities
Settlement of floating-to-fixed interest rate swap and interest rate cap agreement		$ 2.6