Quarterly report pursuant to Section 13 or 15(d)

Goodwill and intangible assets (Details) - Schedule of intangible assets

v3.8.0.1
Goodwill and intangible assets (Details) - Schedule of intangible assets - USD ($)
$ in Thousands
Apr. 30, 2018
Jul. 31, 2017
Goodwill and intangible assets (Details) - Schedule of intangible assets [Line Items]    
Finite-lived intangible assets, Gross $ 27,438 $ 27,436
Finite-lived intangible assets, Accumulated Amortization (25,289) (24,541)
Finite-lived intangible assets, Net 2,149 2,895
Patents [Member]    
Goodwill and intangible assets (Details) - Schedule of intangible assets [Line Items]    
Finite-lived intangible assets, Gross 11,027 11,027
Finite-lived intangible assets, Accumulated Amortization (10,971) (10,951)
Finite-lived intangible assets, Net 56 76
Customer Relationships [Member]    
Goodwill and intangible assets (Details) - Schedule of intangible assets [Line Items]    
Finite-lived intangible assets, Gross 11,892 11,881
Finite-lived intangible assets, Accumulated Amortization (9,799) (9,083)
Finite-lived intangible assets, Net 2,093 2,798
Website And Acquired Content [Member]    
Goodwill and intangible assets (Details) - Schedule of intangible assets [Line Items]    
Finite-lived intangible assets, Gross 1,010 1,011
Finite-lived intangible assets, Accumulated Amortization (1,010) (1,011)
Licensed Technology And Other [Member]    
Goodwill and intangible assets (Details) - Schedule of intangible assets [Line Items]    
Finite-lived intangible assets, Gross 492 484
Finite-lived intangible assets, Accumulated Amortization (492) (463)
Finite-lived intangible assets, Net   21
Trademarks [Member]    
Goodwill and intangible assets (Details) - Schedule of intangible assets [Line Items]    
Finite-lived intangible assets, Gross 3,017 3,033
Finite-lived intangible assets, Accumulated Amortization $ (3,017) $ (3,033)