Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Details)

v3.20.1
Income Taxes - Additional Information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Deferred Tax Assets, Valuation Allowance $ 31,733 $ 25,052
Unrecognized tax benefits interest and penalties accrued 0  
Research and Development Credit Carryforwards [Member]    
Tax Credit Carryforward, Amount 1,000  
Orphan Drug Credit Carryforwards [Member]    
Tax Credit Carryforward, Amount $ 500  
Tax Credit Carryforward, Expiration Date Dec. 31, 2035  
Domestic Tax Authority [Member]    
Operating Loss Carryforwards $ 84,000  
Operating Loss Carry forwards Expiration Period 2035  
State and Local Jurisdiction [Member]    
Operating Loss Carryforwards $ 81,100  
Operating Loss Carry forwards Expiration Period 2035