Annual report pursuant to Section 13 and 15(d)

Summary of significant accounting policies (Details) - Allowance for doubtful accounts

v3.5.0.2
Summary of significant accounting policies (Details) - Allowance for doubtful accounts - USD ($)
$ in Thousands
12 Months Ended
Jul. 31, 2016
Jul. 31, 2015
Jul. 31, 2014
Allowance for doubtful accounts [Abstract]      
Beginning balance $ 1,786 $ 2,142  
Provision for doubtful accounts 2,336 2,284 $ 3,063
Write-offs (605) (2,640)  
Ending balance $ 3,517 $ 1,786 $ 2,142