Summary of the changes in fair value of the Level 3 (Details) - USD ($) $ in Thousands	12 Months Ended
May. 31, 2015	May. 31, 2014
Changes in fair value of the Level 3 classified Holdback Payment Earn-Out Payments asset
Fair value at inception	$ 0	$ 922
Payments received	(604)	(44)
Change in fair value	85	17
Fair value	$ 376	$ 895

Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(3)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration