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, 2013
Jul. 31, 2012
Jul. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]      
Net sales to unaffiliated customers $ 93,707 $ 103,083 $ 102,029
Long-lived assets 26,012 28,348 57,693
UNITED STATES
      
Revenues from External Customers and Long-Lived Assets [Line Items]      
Net sales to unaffiliated customers 80,559 87,776 85,691
Long-lived assets 23,136 25,081 44,028
SWITZERLAND
      
Revenues from External Customers and Long-Lived Assets [Line Items]      
Net sales to unaffiliated customers 5,499 6,802 8,508
Long-lived assets 1,984 2,223 8,958
UNITED KINGDOM
      
Revenues from External Customers and Long-Lived Assets [Line Items]      
Net sales to unaffiliated customers 2,324 2,728 2,825
Long-lived assets 491 618 2,857
Other International Countries [Member]
      
Revenues from External Customers and Long-Lived Assets [Line Items]      
Net sales to unaffiliated customers 5,325 5,777 5,005
Long-lived assets $ 401 $ 426 $ 1,850