Annual report pursuant to Section 13 and 15(d)

Goodwill and intangible assets (Details)

v3.5.0.2
Goodwill and intangible assets (Details) - USD ($)
$ in Thousands
12 Months Ended
Jul. 31, 2016
Jul. 31, 2015
Jul. 31, 2014
Goodwill and intangible assets (Details) [Line Items]      
Goodwill $ 7,452 $ 7,452  
Finite-Lived Intangible Asset, Useful Life 10 years    
Amortization of Intangible Assets $ 1,677 $ 1,770 $ 1,840
Intangible Assets, Amortization Period [Member]      
Goodwill and intangible assets (Details) [Line Items]      
Finite-Lived Intangible Asset, Useful Life 3 years