Quarterly report pursuant to Section 13 or 15(d)

Stock Purchase Warrants (Details Textual)

v3.8.0.1
Stock Purchase Warrants (Details Textual) - USD ($)
1 Months Ended 3 Months Ended
Dec. 26, 2017
Nov. 18, 2016
Oct. 10, 2014
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Equity, Class of Treasury Stock [Line Items]            
Warrants Not Settleable in Cash, Fair Value Disclosure $ 9,000          
Change in fair value of warrant liability       $ (2,655,000) $ (5,090,000)  
Warrant liabilities       1,428,000   $ 4,083,000
Consulting Agreement Term 6 months          
Warrant [Member]            
Equity, Class of Treasury Stock [Line Items]            
Share Based Compensation Arrangement By Share Based Payment Award Non Option Equity Instruments Warrants Exercisable Number 25,000          
Stock Warrants [Member]            
Equity, Class of Treasury Stock [Line Items]            
Sale of Stock, Price Per Share     $ 1.47      
Change in fair value of warrant liability     $ 7,400,000 326,000,000 1,000,000  
Proceeds from Issuance of Common Stock     $ 19,100,000      
Sale of Stock, Number of Shares Issued in Transaction     14,059,616      
Issuance Of Warrants To Purchase Of Common Stock     0.5      
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Exercisable, Number     7,029,808      
Share Based Compensation Arrangement By Share Based Payment Award Warrants Vested and Expected To Vest Outstanding Number     1.75      
Warrant liabilities       90,000 1,100,000  
IPO [Member]            
Equity, Class of Treasury Stock [Line Items]            
Sale of Stock, Price Per Share   $ 1.00        
Stock Issued During Period, Shares, New Issues   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   $ 15,700,000   1,300,000 8,600,000  
Change in fair value of warrant liability       $ 2,300,000 $ 4,100,000  
IPO [Member] | Series A [Member]            
Equity, Class of Treasury Stock [Line Items]            
Class of Warrant or Right, Exercise Price of Warrants or Rights   $ 1.43        
IPO [Member] | Series B [Member]            
Equity, Class of Treasury Stock [Line Items]            
Class of Warrant or Right, Exercise Price of Warrants or Rights   $ 1.72