Annual report pursuant to Section 13 and 15(d)

Income taxes (Details)

v2.4.0.8
Income taxes (Details) (USD $)
 12 Months Ended
Jul. 31, 2014
Jul. 31, 2013
Income taxes (Details) [Line Items]    
Deferred Tax Liabilities, Net $ 183,000 $ 200,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount 1,800,000 6,400,000
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration 103,200,000  
Deferred Tax Assets Research and Development and Other Tax Credit Carryforwards 1,085,000 1,013,000
Foreign Loss Carryforwards 6,000,000  
Undistributed Earnings of Foreign Subsidiaries 304,000  
Liability for Uncertain Tax Position 0  
Domestic Tax Authority [Member] | Minimum [Member]
    
Income taxes (Details) [Line Items]    
Operating Loss Carryforwards Expiration Year 2018  
Domestic Tax Authority [Member] | Maximum [Member]
    
Income taxes (Details) [Line Items]    
Operating Loss Carryforwards Expiration Year 2034  
U.S. Federal Tax [Member]
    
Income taxes (Details) [Line Items]    
Deferred Tax Assets Research and Development and Other Tax Credit Carryforwards $ 1,000,000  
Research Tax Credit Carryforward [Member] | Minimum [Member]
    
Income taxes (Details) [Line Items]    
Tax Credit Carryforward Expiration Year 2025  
Research Tax Credit Carryforward [Member] | Maximum [Member]
    
Income taxes (Details) [Line Items]    
Tax Credit Carryforward Expiration Year 2034  
Minimum [Member]
    
Income taxes (Details) [Line Items]    
Income Tax Examination, Year under Examination 2011  
Maximum [Member]
    
Income taxes (Details) [Line Items]    
Income Tax Examination, Year under Examination 2013