Annual report pursuant to Section 13 and 15(d)

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

v3.3.0.814
Summary of significant accounting policies (Details) - Net accounts receivable by segment - USD ($)
$ in Thousands
Jul. 31, 2015
Jul. 31, 2014
Clinical Labs (by billing category)    
Accounts Receivable Net Current $ 12,109 $ 12,470
Clinical Labs [Member]    
Clinical Labs (by billing category)    
Accounts Receivable Net Current $ 8,194 $ 7,530
Accounts Receivable Net Current Percentage 100.00% 100.00%
Life Sciences [Member]    
Clinical Labs (by billing category)    
Accounts Receivable Net Current $ 3,915 $ 4,940
Third-Party Payor [Member] | Clinical Labs [Member]    
Clinical Labs (by billing category)    
Accounts Receivable Net Current $ 3,595 $ 3,499
Accounts Receivable Net Current Percentage 44.00% 46.00%
Self-Pay [Member] | Clinical Labs [Member]    
Clinical Labs (by billing category)    
Accounts Receivable Net Current $ 3,213 $ 2,193
Accounts Receivable Net Current Percentage 39.00% 29.00%
Medicare [Member] | Clinical Labs [Member]    
Clinical Labs (by billing category)    
Accounts Receivable Net Current $ 1,081 $ 1,558
Accounts Receivable Net Current Percentage 13.00% 21.00%
Health Maintenance Organizations [Member] | Clinical Labs [Member]    
Clinical Labs (by billing category)    
Accounts Receivable Net Current $ 305 $ 280
Accounts Receivable Net Current Percentage 4.00% 4.00%