XML 84 R59.htm IDEA: XBRL DOCUMENT  v2.3.0.11
Fair Value Measurements (Details) (USD $)
In Thousands
Jul. 31, 2011
Jul. 31, 2010
Money Market [Member]
   
Cash equivalents measured at fair value   $ 399
Money Market [Member] | Level 1 [Member]
   
Cash equivalents measured at fair value   399
Money Market [Member] | Level 2 [Member]
   
Cash equivalents measured at fair value    
Money Market [Member] | Level 3 [Member]
   
Cash equivalents measured at fair value    
US Treasury [Member]
   
Cash equivalents measured at fair value 8,381 8,297
US Treasury [Member] | Level 1 [Member]
   
Cash equivalents measured at fair value 8,381 8,297
US Treasury [Member] | Level 2 [Member]
   
Cash equivalents measured at fair value    
US Treasury [Member] | Level 3 [Member]
   
Cash equivalents measured at fair value    
Certificates of Deposit [Member]
   
Cash equivalents measured at fair value 2,490 300
Certificates of Deposit [Member] | Level 1 [Member]
   
Cash equivalents measured at fair value    
Certificates of Deposit [Member] | Level 2 [Member]
   
Cash equivalents measured at fair value 2,490 300
Certificates of Deposit [Member] | Level 3 [Member]
   
Cash equivalents measured at fair value