XML 81 R59.htm IDEA: XBRL DOCUMENT v3.20.1
Stockholders' Equity - February 2018 Financing - Additional Information (Details)
$ / shares in Units, $ in Millions
 1 Months Ended
Sep. 30, 2018
shares
Feb. 28, 2018
USD ($)
$ / shares
shares
Dec. 31, 2019
$ / shares
shares
Dec. 31, 2018
$ / shares
shares
Dec. 21, 2018
USD ($)
Dec. 31, 2017
$ / shares
shares
Stockholders Equity Note [Line Items]            
Sale of common stock, net of expenses (in shares) 6,669 606        
Number of pre-funded warrants   109        
Net proceeds from issuance of private placement | $   $ 4.3        
Number of warrants outstanding (in shares)     1,826,608 93,835   20
Maximum [Member]            
Stockholders Equity Note [Line Items]            
Warrants exercisable per share price (in dollars per share) | $ / shares     $ 23 $ 7,000   $ 13,798,400,000
Minimum [Member]            
Stockholders Equity Note [Line Items]            
Warrants exercisable per share price (in dollars per share) | $ / shares     $ 7 $ 7   $ 857,500
Contractual Term [Member]            
Stockholders Equity Note [Line Items]            
Warrants expiration period     4 years 7 months 6 days      
Contractual Term [Member] | Maximum [Member]            
Stockholders Equity Note [Line Items]            
Warrants expiration period       5 years 1 month 6 days    
Contractual Term [Member] | Minimum [Member]            
Stockholders Equity Note [Line Items]            
Warrants expiration period       1 year 1 month 6 days    
Volatility [Member]            
Stockholders Equity Note [Line Items]            
Warrants measurement input     2.075      
Volatility [Member] | Maximum [Member]            
Stockholders Equity Note [Line Items]            
Warrants measurement input       2.653    
Volatility [Member] | Minimum [Member]            
Stockholders Equity Note [Line Items]            
Warrants measurement input       1.457    
Risk Free Rate [Member]            
Stockholders Equity Note [Line Items]            
Warrants measurement input     0.017      
Risk Free Rate [Member] | Maximum [Member]            
Stockholders Equity Note [Line Items]            
Warrants measurement input       0.026    
Risk Free Rate [Member] | Minimum [Member]            
Stockholders Equity Note [Line Items]            
Warrants measurement input       0.025    
February 2018 Warrants [Member]            
Stockholders Equity Note [Line Items]            
Warrants issued to purchase Common Stock   1,429,000,000        
Value of warrants issued | $   $ 18.3        
Warrants exercisable per share price (in dollars per share) | $ / shares   $ 7,000        
Number of warrants outstanding (in shares)   273        
February 2018 Warrants [Member] | Exercise Price [Member]            
Stockholders Equity Note [Line Items]            
Warrants measurement input | $ / shares   7,000        
February 2018 Warrants [Member] | Contractual Term [Member]            
Stockholders Equity Note [Line Items]            
Warrants expiration period   6 years        
February 2018 Warrants [Member] | Volatility [Member]            
Stockholders Equity Note [Line Items]            
Warrants measurement input   1.2268        
February 2018 Warrants [Member] | Risk Free Rate [Member]            
Stockholders Equity Note [Line Items]            
Warrants measurement input   0.01        
Pre-Funded Series D Warrants [Member] | Maximum [Member]            
Stockholders Equity Note [Line Items]            
Maximum offering and selling of stock and securities that entity make to raise capital | $         $ 100.0