Annual report pursuant to Section 13 and 15(d)

Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details)

v3.3.1.900
Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details)
12 Months Ended
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Dec. 31, 2013
USD ($)
Dec. 31, 2012
USD ($)
Advertising        
Advertising Expense $ 300,000 $ 300,000 $ 500,000  
Cash, Cash Equivalents and Marketable Securities [Abstract]        
Cash and cash equivalents 23,273,000 26,487,000 22,130,000 $ 32,003,000
Cash 12,153,000 11,885,000    
Money market funds 11,120,000 14,602,000    
Accounts receivable - past due & future payments 3,100,000      
Intangible Assets, Net (Excluding Goodwill) [Abstract]        
Impairment of laboratory equipment $ 0 1,841,000    
Number of operating segments 1      
Goodwill impairment $ 0 $ 0 $ 0