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

Fair Value Measurement - Additional Information (Details)

v3.21.2
Fair Value Measurement - Additional Information (Details)
$ in Thousands
 9 Months Ended 12 Months Ended
Sep. 30, 2021
USD ($)
Milestone
Dec. 31, 2020
USD ($)
Milestone
Dec. 31, 2019
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash equivalents   $ 2,474  
Business Combination, Contingent Consideration, Number Of Technical Milestone | Milestone 4 4  
Level 1 | Money market funds and time deposits      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash equivalents   $ 2,500 $ 2,500
Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash equivalents $ 11,725 2,474 2,473
Recurring | Level 1      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash equivalents 11,725 2,474 $ 2,473
Recurring | Level 1 | Money market funds and time deposits      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash equivalents $ 11,700 $ 2,500  
Discount rate      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Fair value inputs 13.5    
Revenue Volatility      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Fair value inputs 29.0