Quarterly report pursuant to Section 13 or 15(d)

Organization and Summary of Significant Accounting Policies (Details Textual)

v3.7.0.1
Organization and Summary of Significant Accounting Policies (Details Textual) - USD ($)
 1 Months Ended 3 Months Ended 6 Months Ended
Jul. 27, 2017
May 31, 2016
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Schedule of Organization and Summary of Significant Accounting Policies [Line Items]            
Less change in fair value of warrant liability     $ 190,000 $ (110,000) $ 612,000 $ (106,000)
Investments, Fair Value Disclosure     $ 8,400,000   $ 8,400,000  
Revenue Recognition, Milestone Method, Revenue Recognized   $ 15,000,000        
Subsequent Event [Member]            
Schedule of Organization and Summary of Significant Accounting Policies [Line Items]            
Proceeds from (Repayments of) Debt $ 6,800,000          
Horizon Technology Finance Corporation [Member] | Venture Loan [Member] | Subsequent Event [Member]            
Schedule of Organization and Summary of Significant Accounting Policies [Line Items]            
Debt Instrument, Face Amount 7,000,000          
Debt Instrument, Additional Face Amount 3,000,000          
Minimum [Member] | Horizon Technology Finance Corporation [Member] | Venture Loan [Member] | Subsequent Event [Member]            
Schedule of Organization and Summary of Significant Accounting Policies [Line Items]            
Debt Instrument, Face Amount $ 10,000,000