Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Warrant (Details)

v3.19.1
Stockholders' Equity - Warrant (Details) - USD ($)
12 Months Ended
Jun. 19, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Sep. 19, 2018
Jul. 21, 2017
Jun. 30, 2017
Class of Warrant or Right [Line Items]              
Common stock, par value (in dollars per share)   $ 0.0001 $ 0.0001       $ 0.0001
Common stock, shares issued (in shares)   27,568,656 27,707,328        
Series A-1 warrant liability   $ 0 $ 3,313,000 $ 0      
Change in fair value of warrant liability   3,445,000 $ (2,217,000) $ 0      
Aggregate intrinsic value of the warrant   $ 0          
Common Stock Warrant              
Class of Warrant or Right [Line Items]              
Common stock, par value (in dollars per share) $ 0.0001            
Right to acquire variable amount of common stock, term 15 months            
Common Stock Warrant | Soryn HLDR              
Class of Warrant or Right [Line Items]              
Exercise price (in dollars per share) $ 3.18            
Term of warrant 3 years 1 year 6 months          
Series A-1 warrant liability $ 3,300,000            
Common Stock | Common Stock Warrant | Soryn HLDR              
Class of Warrant or Right [Line Items]              
Common stock warrant purchased (shares) 2,000,000 2,355,506          
Common stock, shares issued (in shares) 2,000,000         50,000 300,000
Series A-1 warrant liability         $ 4,500,000    
Change in fair value of warrant liability   $ (3,400,000)