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, 2014
Jul. 31, 2013
Summary of significant accounting policies (Details) - Net accounts receivable by segment [Line Items]    
Accounts Receivable Net Current $ 12,470 $ 12,288
Clinical Labs [Member] | Third-Party Payor [Member]
    
Summary of significant accounting policies (Details) - Net accounts receivable by segment [Line Items]    
Accounts Receivable Net Current 3,499 3,395
Accounts Receivable Net Current Percentage 46.00% 46.00%
Clinical Labs [Member] | Self-Pay [Member]
    
Summary of significant accounting policies (Details) - Net accounts receivable by segment [Line Items]    
Accounts Receivable Net Current 2,193 2,696
Accounts Receivable Net Current Percentage 29.00% 37.00%
Clinical Labs [Member] | Medicare [Member]
    
Summary of significant accounting policies (Details) - Net accounts receivable by segment [Line Items]    
Accounts Receivable Net Current 1,558 930
Accounts Receivable Net Current Percentage 21.00% 13.00%
Clinical Labs [Member] | Health Maintenance Organizations [Member]
    
Summary of significant accounting policies (Details) - Net accounts receivable by segment [Line Items]    
Accounts Receivable Net Current 280 300
Accounts Receivable Net Current Percentage 4.00% 4.00%
Clinical Labs [Member]
    
Summary of significant accounting policies (Details) - Net accounts receivable by segment [Line Items]    
Accounts Receivable Net Current 7,530 7,321
Accounts Receivable Net Current Percentage 100.00% 100.00%
Life Sciences [Member]
    
Summary of significant accounting policies (Details) - Net accounts receivable by segment [Line Items]    
Accounts Receivable Net Current $ 4,940 $ 4,967