Quarterly report pursuant to Section 13 or 15(d)

Customer Concentrations - Additional Information (Detail)

v3.21.2
Customer Concentrations - Additional Information (Detail) - Customer Concentration Risk [Member] - Customer
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Revenues [Member]          
Concentration Risk [Line Items]          
Number of customers 2 4 4 3  
Concentration percentage 61.00% 81.00% 62.00% 78.00%  
Accounts Receivable [Member]          
Concentration Risk [Line Items]          
Number of customers     2   4
Concentration percentage     70.00%   92.00%