Quarterly report pursuant to Section 13 or 15(d)

Stock Purchase Warrants (Details Textual)

v3.10.0.1
Stock Purchase Warrants (Details Textual) - USD ($)
1 Months Ended 3 Months Ended 9 Months Ended
Nov. 18, 2016
Oct. 10, 2014
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Dec. 26, 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     $ (626,000) $ 5,092,000 $ (4,064,000) $ (2,157,000)    
Warrant liabilities     19,000   19,000   $ 4,083,000  
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               714
Stock Warrants [Member]                
Equity, Class of Treasury Stock [Line Items]                
Sale of Stock, Price Per Share   $ 51.45            
Change in fair value of warrant liability   $ 7,400,000 21,000 1,000,000 415,000 200,000    
Proceeds from Issuance of Common Stock   $ 19,100,000            
Sale of Stock, Number of Shares Issued in Transaction   401,703            
Issuance Of Warrants To Purchase Of Common Stock   0.5            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number   61.25            
Share Based Compensation Arrangement By Share Based Payment Award Warrants Vested and Expected To Vest Outstanding Number   200,852            
Warrant liabilities       2,000,000   2,000,000    
IPO [Member]                
Equity, Class of Treasury Stock [Line Items]                
Sale of Stock, Price Per Share $ 35              
Stock Issued During Period, Shares, New Issues 714,286              
Class of Warrant or Right, Number of Securities Called by Warrants or Rights 1,428,571,000,000              
Warrants Not Settleable in Cash, Fair Value Disclosure $ 15,700,000   19,000 10,700,000 19,000 10,700,000    
Change in fair value of warrant liability     $ 605,000 $ 4,100,000 $ 3,600,000 $ 2,000,000    
IPO [Member] | Series A [Member]                
Equity, Class of Treasury Stock [Line Items]                
Class of Warrant or Right, Exercise Price of Warrants or Rights $ 50.05              
IPO [Member] | Series B [Member]                
Equity, Class of Treasury Stock [Line Items]                
Class of Warrant or Right, Exercise Price of Warrants or Rights $ 60.20