Annual report pursuant to Section 13 and 15(d)

Customer Concentration - Additional Information (Detail)

v3.20.1
Customer Concentration - Additional Information (Detail) - Customer Concentration Risk [Member] - Customer
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Revenues [Member]    
Concentration Risk [Line Items]    
Number of customers 4 1
Concentration percentage 52.00% 92.00%
Accounts Receivable [Member]    
Concentration Risk [Line Items]    
Number of customers 4 3
Concentration percentage 100.00% 86.00%