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

Debt - Summary of Debt (Detail)

v3.21.2
Debt - Summary of Debt (Detail) - USD ($)
$ in Thousands
Sep. 30, 2021
Dec. 31, 2020
Dec. 31, 2019
Debt Instrument, Redemption [Line Items]      
Total debt $ 46,755 $ 154 $ 2,497
Unamortized deferred financing costs, Cargill Loan (655)    
Less: current portion   (50) 0
Convertible notes with fair value adjustment ($26,050 thousand in face value) 31,117    
Long-term debt, less current portion and convertible notes 15,638 104 2,497
Promissory notes [Member]      
Debt Instrument, Redemption [Line Items]      
Total debt   0 2,497
PPP loan [Member]      
Debt Instrument, Redemption [Line Items]      
Total debt   104 0
Share settlement note [Member]      
Debt Instrument, Redemption [Line Items]      
Total debt   50 $ 0
Less: current portion   $ (50)  
Cargill Loan [Member]      
Debt Instrument, Redemption [Line Items]      
Total debt $ 16,293