General form of registration statement for all companies including face-amount certificate companies

Income Taxes - Additional Information (Detail)

v3.21.2
Income Taxes - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Income Tax Examination [Line Items]    
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount $ 37.1 $ 32.6
Percentage of ownership changes in common stock 5.00%  
Federal research and development credits [Member]    
Income Tax Examination [Line Items]    
Tax Credit Carryforward Amount $ 10.5  
Tax Credit Carryforward, ExpirationYear 2036 years  
California research and development credits [Member]    
Income Tax Examination [Line Items]    
Tax Credit Carryforward Amount $ 9.5  
federal tax Authority [Member]    
Income Tax Examination [Line Items]    
Operating Loss Carryforwards 261.4 150.8
State and Local Jurisdiction [Member]    
Income Tax Examination [Line Items]    
Operating Loss Carryforwards 256.0 $ 148.6
Operating Loss Carryforwards, Expiration Year   2036 years
Foreign Tax Authority [Member]    
Income Tax Examination [Line Items]    
Operating Loss Carryforwards $ 0.2  
Maximum [Member]    
Income Tax Examination [Line Items]    
Operating Loss Carryforwards, Expiration Year 2037 years 2037 years
Minimum [Member]    
Income Tax Examination [Line Items]    
Operating Loss Carryforwards, Expiration Year 2036 years 2036 years
Weighted Average [Member]    
Income Tax Examination [Line Items]    
Operating Loss Carryforwards $ 15.8 $ 15.8