Annual report pursuant to Section 13 and 15(d)

Employee benefit plan (Details)

v3.7.0.1
Employee benefit plan (Details) - USD ($)
$ in Thousands
12 Months Ended
Jul. 31, 2017
Jul. 31, 2016
Jul. 31, 2015
Employee benefit plan (Details) [Line Items]      
Employer Matched Contributions Percentage Of The Employees Contribution 50.00% 50.00% 50.00%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent 10.00% 10.00% 10.00%
Share Based 401k Employer Match Expense (in Dollars) $ 724 $ 709 $ 662
Defined Benefit Plan, Contribution in Accrued Liabilities (in Dollars) $ 412 $ 413 $ 387
Defined Contribution Plan Minimum Annual Contribution Percent 13.00%    
Minimum Age of Employee for Saving Contribution 25 years    
Defined Benefit Plan Minimum Annual Investment Return Percentage 1.00%    
Defined Contribution Pension Plan Expiration Date Dec. 31, 2019    
Swiss Employees [Member]      
Employee benefit plan (Details) [Line Items]      
Employer Matched Contributions Percentage Of The Employees Contribution 50.00%