Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Details)

v3.20.4
Income Taxes - Additional Information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Deferred Tax Assets, Valuation Allowance $ 37,275 $ 31,733
Unrecognized tax benefits interest and penalties accrued 0 $ 0
Research and Development Credit Carryforwards [Member]    
Tax Credit Carryforward, Amount 1,100  
Orphan Drug Credit Carryforwards [Member]    
Tax Credit Carryforward, Amount $ 700  
Tax Credit Carryforward, Expiration Date Dec. 31, 2035  
Domestic Tax Authority [Member]    
Operating Loss Carryforwards $ 101,100  
Operating Loss Carry forwards Expiration Period 2035  
Federal [Member]    
Operating Loss Carryforwards $ 69,900  
Tax Credit Carryforward, Amount 31,200  
State and Local Jurisdiction [Member]    
Operating Loss Carryforwards $ 94,900  
Operating Loss Carry forwards Expiration Period 2035