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

Summary of Significant Accounting Policies - Summary of Customers Whose Revenue and Accounts Receivable Balances (Detail)

v3.21.2
Summary of Significant Accounting Policies - Summary of Customers Whose Revenue and Accounts Receivable Balances (Detail) - Customer Concentration Risk [Member]
 6 Months Ended 12 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Revenue | Customer A        
Concentration Risk [Line Items]        
Concentration Customer Risk, Percentage 30.00% 40.00% 36.00% 47.00%
Revenue | Customer B        
Concentration Risk [Line Items]        
Concentration Customer Risk, Percentage 20.00% 22.00% 21.00% 10.00%
Revenue | Customer C        
Concentration Risk [Line Items]        
Concentration Customer Risk, Percentage 12.00%     14.00%
Accounts Receivable | Customer A        
Concentration Risk [Line Items]        
Concentration Customer Risk, Percentage 33.00%   67.00% 78.00%
Accounts Receivable | Customer C        
Concentration Risk [Line Items]        
Concentration Customer Risk, Percentage 25.00%