Basis of Presentation - Fair Value of Foreign Exchange Forward Contracts (Detail) - USD ($) $ in Thousands	Feb. 29, 2016	May. 31, 2015
Derivatives Not Designated as Hedging Instruments \| Foreign exchange forward contracts \| Accrued Expenses
Derivatives Not Designated as Hedging Instruments
Foreign exchange forward contracts Other assets	$ (18)	$ (16)

Fair value as of the balance sheet date of all foreign currency derivative liabilities not designated 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 4B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624163-113959

Name:	us-gaap_ForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant