Annual report pursuant to Section 13 and 15(d)

Income Taxes (Details)

v3.21.1
Income Taxes (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Income Taxes (Details) [Line Items]    
Deferred tax assets, valuation allowance $ 56.2 $ 49.9
Federal income tax purposes, net operating losses $ 152.0  
Description of limitation of net loss limited to 80% of their value if used in a tax year ending after January 1, 2021.  
State income tax purposes, net operating losses $ 81.7  
Research Tax Credit Carryforward [Member] | Domestic Tax Authority [Member]    
Income Taxes (Details) [Line Items]    
Net operating losses $ 2.2  
Net operating loss expiration date expire in 2034  
Orphan Drug Credits [Member]    
Income Taxes (Details) [Line Items]    
Net operating losses $ 10.4  
Net operating loss expiration date expire in 2028