Annual report pursuant to Section 13 and 15(d)

Summary of significant accounting policies (Details) - Net accounts receivable by segment

v2.4.0.8
Summary of significant accounting policies (Details) - Net accounts receivable by segment (USD $)
In Thousands, unless otherwise specified
Jul. 31, 2013
Jul. 31, 2012
Clinical Labs (by billing category)    
Accounts Receivable Net Current $ 12,288 $ 14,135
Clinical Labs [Member] | Medicare
   
Clinical Labs (by billing category)    
Accounts Receivable Net Current 930 1,270
Accounts Receivable Net Current Percentage 13.00% 16.00%
Clinical Labs [Member] | Third-Party Payor [Member]
   
Clinical Labs (by billing category)    
Accounts Receivable Net Current 3,395 3,478
Accounts Receivable Net Current Percentage 46.00% 45.00%
Clinical Labs [Member] | Self-Pay [Member]
   
Clinical Labs (by billing category)    
Accounts Receivable Net Current 2,696 2,655
Accounts Receivable Net Current Percentage 37.00% 35.00%
Clinical Labs [Member] | Health Maintenance Organizations
   
Clinical Labs (by billing category)    
Accounts Receivable Net Current 300 330
Accounts Receivable Net Current Percentage 4.00% 4.00%
Clinical Labs [Member]
   
Clinical Labs (by billing category)    
Accounts Receivable Net Current 7,321 7,733
Accounts Receivable Net Current Percentage 100.00% 100.00%
Life Sciences [Member]
   
Clinical Labs (by billing category)    
Accounts Receivable Net Current $ 4,967 $ 6,402