Annual report pursuant to Section 13 and 15(d)

Summary of significant accounting policies (Details)

v3.3.0.814
Summary of significant accounting policies (Details)
 12 Months Ended
Jul. 31, 2015
USD ($)
shares
Jul. 31, 2014
USD ($)
shares
Jul. 31, 2013
USD ($)
shares
Jul. 31, 2012
USD ($)
Summary of significant accounting policies (Details) [Line Items]        
Number of Operating Segments 3      
Cash and Cash Equivalents, at Carrying Value $ 18,109,000 $ 17,455,000 $ 9,007,000 $ 15,076,000
Contractual Adjustment Percentage 85.00% 86.00% 85.00%  
Minimum Collection Period for Outstanding Accounts Receivable 210 days 210 days    
Percentage Of Account Receivable Over Specified Days 100.00% 100.00%    
Maximum Period for Allowance for Doubtful Accounts 210 days 210 days    
Percentage of Doubtful Accounts to Accounts Receivable 12.90% 14.70%    
Other Receivables, Net, Current $ 6,650,000      
Finite-Lived Intangible Asset, Useful Life 10 years      
Impairment of Long-Lived Assets Held-for-use $ 0 $ 0 $ 0  
Advertising Expense 556,000 440,000 302,000  
Share-based Compensation 429,000 594,000 545,000  
Excess Tax Benefit from Share-based Compensation, Operating Activities 0 $ 0 $ 0  
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options $ 555,000      
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition 15 months      
Outstanding Options [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in Shares) | shares 977,000 182,000 727,000  
Foreign Bank [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Cash and Cash Equivalents, at Carrying Value $ 500,000 $ 1,100,000    
Clinical Labs [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Receivable Percentage   60.00%    
Clinical Labs [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Sales Revenue Services Net Percentage 100.00% 100.00% 100.00%  
Receivable Percentage 68.00%      
Life Sciences [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Royalties Receivable $ 100,000 $ 1,000,000    
Agreement [Member] | Life Sciences [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Other Receivables, Net, Current $ 6,650,000      
Minimum [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Finite-Lived Intangible Asset, Useful Life 4 years      
Minimum [Member] | Building and Building Improvements [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Property, Plant and Equipment, Estimated Useful Lives 15      
Minimum [Member] | Machinery and Equipment [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Property, Plant and Equipment, Estimated Useful Lives 3      
Maximum [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Finite-Lived Intangible Asset, Useful Life 15 years      
Maximum [Member] | Building and Building Improvements [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Property, Plant and Equipment, Estimated Useful Lives 30      
Maximum [Member] | Machinery and Equipment [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Property, Plant and Equipment, Estimated Useful Lives 10      
In the Money Stock Options [Member] | Unvested Restricted Stock [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in Shares) | shares 403,000 1,016,000 125,000  
United Health Care of New York [Member] | Clinical Labs [Member]        
Summary of significant accounting policies (Details) [Line Items]        
Sales Revenue Services Net Percentage 28.00% 25.00% 22.00%