Annual report pursuant to Section 13 and 15(d)

Summary of significant accounting policies (Details)

v2.4.0.8
Summary of significant accounting policies (Details) (USD $)
Share data in Thousands, unless otherwise specified
 12 Months Ended
Jul. 31, 2013
Jul. 31, 2012
Jul. 31, 2011
Jul. 31, 2010
Summary of significant accounting policies (Details) [Line Items]        
Number of Operating Segments 3      
Maximum Maturity Period of Cash and Cash Equivalents 90 days      
Cash and Cash Equivalents, at Carrying Value (in Dollars) $ 9,007,000 $ 15,076,000 $ 14,161,000 $ 8,759,000
Contractual Adjustment Percentage 85.00% 85.00% 84.00%  
Maximum Period for Allowance for Doubtful Accounts 210 days 210 days    
Percentage Of Account Receivable Over Specified Days 100.00% 100.00%    
Impairment of Long-Lived Assets Held-for-use (in Dollars)   0 0  
Finite-Lived Intangible Asset, Useful Life 10 years      
Advertising Expense (in Dollars) 302,000 237,000 235,000  
Unvested Restricted Stock Excluded From Calculation of Diluted Earnings Per Share (in Shares) 32,000 0 27,000  
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in Shares) 727,000 736,000 785,000  
Share-based Compensation (in Dollars) 545,000 719,000 1,049,000  
Excess Tax Benefit from Share-based Compensation, Operating Activities (in Dollars) 0 0 0  
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options (in Dollars) 531,000      
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition 15 months      
Indefinite-Lived Intangible Assets (Excluding Goodwill) (in Dollars) 0      
Clinical Labs [Member] | Another Third Party Provider [Member]
        
Summary of significant accounting policies (Details) [Line Items]        
Sales Revenue Services Net Percentage 9.00% 13.00% 11.00%  
Clinical Labs [Member] | United Health Care of New York [Member]
        
Summary of significant accounting policies (Details) [Line Items]        
Sales Revenue Services Net Percentage 22.00% 21.00% 22.00%  
Clinical Labs [Member]
        
Summary of significant accounting policies (Details) [Line Items]        
Sales Revenue Services Net Percentage 100.00% 100.00% 100.00%  
Receivable Percentage 60.00% 55.00%    
Life Sciences [Member]
        
Summary of significant accounting policies (Details) [Line Items]        
Royalties Receivable (in Dollars) 1,200,000 1,700,000    
Building and Building Improvements [Member] | Minimum [Member]
        
Summary of significant accounting policies (Details) [Line Items]        
Property, Plant and Equipment, Estimated Useful Lives 15      
Building and Building Improvements [Member] | Maximum [Member]
        
Summary of significant accounting policies (Details) [Line Items]        
Property, Plant and Equipment, Estimated Useful Lives 30      
Machinery and Equipment [Member] | Minimum [Member]
        
Summary of significant accounting policies (Details) [Line Items]        
Property, Plant and Equipment, Estimated Useful Lives 3      
Machinery and Equipment [Member] | Maximum [Member]
        
Summary of significant accounting policies (Details) [Line Items]        
Property, Plant and Equipment, Estimated Useful Lives 10      
Foreign Bank [Member]
        
Summary of significant accounting policies (Details) [Line Items]        
Cash and Cash Equivalents, at Carrying Value (in Dollars) $ 1,500,000 $ 2,500,000    
Minimum [Member]
        
Summary of significant accounting policies (Details) [Line Items]        
Finite-Lived Intangible Asset, Useful Life 4 years      
Maximum [Member]
        
Summary of significant accounting policies (Details) [Line Items]        
Finite-Lived Intangible Asset, Useful Life 15 years