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

Concentrations, Risks, and Uncertainties - Additional Information (Detail)

v3.21.2
Concentrations, Risks, and Uncertainties - Additional Information (Detail) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Concentration Risk [Line Items]            
Concentration risk percentage     10.00%   10.00% 10.00%
Revenue $ 7,937 $ 5,317 $ 22,596 $ 14,728 $ 21,135 $ 13,713
Accounts receivable 4,909   4,909   2,903 4,328
Accounts Receivable [Member]            
Concentration Risk [Line Items]            
Revenue         15,600 9,300
Accounts receivable         2,000 3,100
Accounts Receivable [Member] | Continuing Operations [Member] | Customer Concentration Risk [Member]            
Concentration Risk [Line Items]            
Accounts receivable 3,200   3,200   2,000  
Accounts Receivable [Member] | Continuing Operations [Member] | Government Contracts Concentration Risk [Member]            
Concentration Risk [Line Items]            
Accounts receivable $ 4,600   4,600   1,300  
Federal Government And Agencies [Member]            
Concentration Risk [Line Items]            
Revenue         17,100 11,700
Accounts receivable         1,300 $ 3,300
Sales Revenue Net [Member] | Continuing Operations [Member] | Customer Concentration Risk [Member]            
Concentration Risk [Line Items]            
Revenue     9,300   $ 11,700  
Sales Revenue Net [Member] | Continuing Operations [Member] | Government Contracts Concentration Risk [Member]            
Concentration Risk [Line Items]            
Revenue     $ 18,900 $ 11,700