Stockholders' Equity (Details 5) $ in Thousands	May. 31, 2015 USD ($)
Summary of future expense for awards outstanding
Stock options Unrecognized Compensation Cost	$ 3,471

Unrecognized cost of unvested options awarded to employees as compensation.

No definition available.

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant