Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation (Details Textual)

v3.6.0.2
Stock-Based Compensation (Details Textual) - USD ($)
1 Months Ended 12 Months Ended
Oct. 10, 2014
Nov. 18, 2017
Dec. 31, 2016
Nov. 18, 2016
Oct. 25, 2012
Mar. 20, 2007
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2001
Aug. 25, 2016
May 15, 2015
Oct. 22, 2013
Nov. 02, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options     $ 6,400,000       $ 6,400,000              
Employee Service Share-based Compensation, Cash Received from Exercise of Stock Options             814,000 $ 41,000 $ 4,000          
Sale of Stock, Price Per Share       $ 1.00                    
Proceeds from Issuance of Common Stock             25,000,000 46,000,000 20,668,000          
Change in fair value of warrant liabilities             (11,412,000) 3,811,000 (620,000)          
Warrant liabilities     $ 14,821,000       $ 14,821,000 $ 10,567,000 $ 6,756,000          
Class of Warrant or Right, Outstanding     311,834       311,834              
IPO [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Sale of Stock, Price Per Share       $ 1.00                    
Change in fair value of warrant liabilities             $ 3,000,000              
Stock Issued During Period, Shares, New Issues 14,059,616 25,000,000   25,000,000                    
Class of Warrant or Right, Number of Securities Called by Warrants or Rights       50,000,000                    
Warrants Not Settleable in Cash, Fair Value Disclosure     $ 12,700,000 $ 15,700,000     $ 12,700,000              
Series A Warrants [Member] | IPO [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Class of Warrant or Right, Exercise Price of Warrants or Rights       $ 1.43                    
Series B Warrants [Member] | IPO [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Investment Warrants Expiration Date     Dec. 31, 2017 Dec. 31, 2017                    
Class of Warrant or Right, Exercise Price of Warrants or Rights       $ 1.72                    
Class Of Warrants Or rights Expiration Period       4 years                    
Warrant [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Issuance of Warrants to Purchase of Common Stock         635,855                  
Warrants Exercise Price Per Share         $ 1.60                  
Employees And Directors [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross             3,861,425 3,781,666 2,382,500          
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value             $ 3,100,000 $ 8,000,000 $ 5,000,000          
Employee [Member] | General and Administrative Expenses and Research and Development Expense [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Allocated Share-based Compensation Expense             3,400,000 2,300,000 2,100,000          
Consultant [Member] | General and Administrative Expenses and Research and Development Expense [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Allocated Share-based Compensation Expense             $ 603,000 888,000 380,000          
2001 Stock Plan [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number     228,773       228,773              
2001 Stock Plan [Member] | Maximum [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross                   250,000        
2007 Stock Plan [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number     659,988     2,500,000 659,988              
2007 Stock Plan [Member] | Maximum [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross           250,000                
2010 Stock Plan [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number     10,747,466       10,747,466             3,000,000
2010 Stock Plan [Member] | Maximum [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Common Stock, Capital Shares Reserved for Future Issuance                     14,000,000 8,000,000 6,000,000  
2010 Stock Plan [Member] | Minimum [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Common Stock, Capital Shares Reserved for Future Issuance                     8,000,000 6,000,000 3,000,000  
Stock Warrants [Member]                            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Issuance of Warrants to Purchase of Common Stock 0.5                          
Share-based Compensation Arrangement by Share-based Payment Award, Warrants, Vested and Expected to Vest Outstanding, Number 1.75                          
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number 7,029,808                          
Sale of Stock, Number of Shares Issued in Transaction 14,059,616                          
Sale of Stock, Price Per Share $ 1.47                          
Proceeds from Issuance of Common Stock $ 19,100,000                          
Change in fair value of warrant liabilities $ 7,400,000             8,500,000 $ 3,800,000          
Warrant liabilities     $ 2,100,000       $ 2,100,000 $ 10,600,000