Annual report pursuant to Section 13 and 15(d)

Segment reporting (Details) - Geographic financial information

v3.10.0.1
Segment reporting (Details) - Geographic financial information - USD ($)
$ in Thousands
 12 Months Ended
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]      
Revenues $ 104,713 $ 107,804 $ 102,773
Long-lived assets 16,974 18,248  
UNITED STATES      
Revenues from External Customers and Long-Lived Assets [Line Items]      
Revenues 95,388 99,469 94,016
Long-lived assets 16,210 17,241  
SWITZERLAND      
Revenues from External Customers and Long-Lived Assets [Line Items]      
Revenues 2,584 2,371 2,709
Long-lived assets 502 649  
UNITED KINGDOM      
Revenues from External Customers and Long-Lived Assets [Line Items]      
Revenues 1,851 1,673 1,730
Long-lived assets 127 185  
Other International Countries [Member]      
Revenues from External Customers and Long-Lived Assets [Line Items]      
Revenues 4,890 4,291 $ 4,318
Long-lived assets $ 135 $ 173