Annual report pursuant to Section 13 and 15(d)

Summary of significant accounting policies (Details) - Segment's net revenues and revenue percentages

v3.3.0.814
Summary of significant accounting policies (Details) - Segment's net revenues and revenue percentages - USD ($)
$ in Thousands
 12 Months Ended
Jul. 31, 2015
Jul. 31, 2014
Jul. 31, 2013
Summary of significant accounting policies (Details) - Segment's net revenues and revenue percentages [Line Items]      
Sales Revenue Services Net $ 63,414 $ 58,689 $ 55,889
Clinical Labs [Member]      
Summary of significant accounting policies (Details) - Segment's net revenues and revenue percentages [Line Items]      
Sales Revenue Services Net $ 63,414 $ 58,689 $ 55,889
Sales Revenue Services Net Percentage 100.00% 100.00% 100.00%
Third-Party Payor [Member] | Clinical Labs [Member]      
Summary of significant accounting policies (Details) - Segment's net revenues and revenue percentages [Line Items]      
Sales Revenue Services Net $ 35,631 $ 29,509 $ 26,014
Sales Revenue Services Net Percentage 56.00% 50.00% 47.00%
Medicare [Member] | Clinical Labs [Member]      
Summary of significant accounting policies (Details) - Segment's net revenues and revenue percentages [Line Items]      
Sales Revenue Services Net $ 11,981 $ 12,815 $ 12,497
Sales Revenue Services Net Percentage 19.00% 22.00% 22.00%
Self-Pay [Member] | Clinical Labs [Member]      
Summary of significant accounting policies (Details) - Segment's net revenues and revenue percentages [Line Items]      
Sales Revenue Services Net $ 11,028 $ 11,204 $ 12,172
Sales Revenue Services Net Percentage 17.00% 19.00% 22.00%
Health Maintenance Organizations [Member] | Clinical Labs [Member]      
Summary of significant accounting policies (Details) - Segment's net revenues and revenue percentages [Line Items]      
Sales Revenue Services Net $ 4,774 $ 5,161 $ 5,206
Sales Revenue Services Net Percentage 8.00% 9.00% 9.00%