Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Additional Information (Details)

v3.19.1
Summary of Significant Accounting Policies - Additional Information (Details)
12 Months Ended
Dec. 31, 2018
USD ($)
license_agreement
Dec. 31, 2017
USD ($)
license_agreement
Dec. 31, 2016
USD ($)
license_agreement
Jan. 01, 2019
USD ($)
Jan. 01, 2018
USD ($)
CONCENTRATIONS OF CREDIT RISK          
Number of license agreements generating revenue | license_agreement 3 6 3    
ALLOWANCE FOR DOUBTFUL ACCOUNTS          
Bad debt expense $ 0 $ 0 $ 0    
DERIVATIVE LIABILITIES          
Reclassification of warrant liability to equity 4,541,000 0 $ 0    
RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS          
Retained earnings $ 26,142,000 $ 5,555,000      
Minimum          
PROPERTY AND EQUIPMENT, NET          
Useful life (in years) 3 years        
Maximum          
PROPERTY AND EQUIPMENT, NET          
Useful life (in years) 7 years        
Accounting Standards Update 2014-09          
RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS          
Retained earnings $ 26,142,000       $ 8,105,000
Accounting Standards Update 2014-09 | Effect of change          
RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS          
Cumulative effect on retained earnings         2,600,000
Retained earnings $ 3,228,000       $ 2,550,000
Revenue | Product Concentration Risk          
CONCENTRATIONS OF CREDIT RISK          
Number of license agreements generating revenue | license_agreement 2   1    
Concentration risk, percentage 95.00% 67.00% 59.00%    
Dividend yield          
DERIVATIVE LIABILITIES          
Measurement input 0        
Fair Value, Inputs, Level 2          
DERIVATIVE LIABILITIES          
Available-for-sale investments   $ 0      
Fair Value, Inputs, Level 2 | Financial and industrial securities          
DERIVATIVE LIABILITIES          
Available-for-sale investments $ 10,200,000        
Fair Value, Inputs, Level 2 | Asset-backed Securities          
DERIVATIVE LIABILITIES          
Available-for-sale investments $ 1,100,000        
Forecast | Subsequent Event | Accounting Standards Update 2016-02 | Minimum          
RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS          
Leased assets       $ 2,700,000  
Lease liability       2,800,000  
Forecast | Subsequent Event | Accounting Standards Update 2016-02 | Maximum          
RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS          
Leased assets       2,900,000  
Lease liability       $ 2,900,000