Annual report pursuant to Section 13 and 15(d)

Segment reporting (Details) - Geographic financial information

v2.4.0.8
Segment reporting (Details) - Geographic financial information (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Jul. 31, 2014
Jul. 31, 2013
Jul. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]      
Net sales to unaffiliated customers $ 95,947 $ 93,707 $ 103,083
Long-lived assets at July 31,      
Long-lived assets 23,290 26,012 28,348
UNITED STATES
     
Revenues from External Customers and Long-Lived Assets [Line Items]      
Net sales to unaffiliated customers 84,389 80,559 87,776
Long-lived assets at July 31,      
Long-lived assets 20,854 23,136 25,081
SWITZERLAND
     
Revenues from External Customers and Long-Lived Assets [Line Items]      
Net sales to unaffiliated customers 4,130 5,499 6,802
Long-lived assets at July 31,      
Long-lived assets 1,629 1,984 2,223
UNITED KINGDOM
     
Revenues from External Customers and Long-Lived Assets [Line Items]      
Net sales to unaffiliated customers 2,023 2,324 2,728
Long-lived assets at July 31,      
Long-lived assets 462 491 618
Other International Countries [Member]
     
Revenues from External Customers and Long-Lived Assets [Line Items]      
Net sales to unaffiliated customers 5,405 5,325 5,777
Long-lived assets at July 31,      
Long-lived assets $ 345 $ 401 $ 426