Quarterly report pursuant to Section 13 or 15(d)

Concentration of credit risk and off-balance sheet risk (Details)

v3.20.2
Concentration of credit risk and off-balance sheet risk (Details) - Customer Concentration Risk [Member] - Customer
6 Months Ended 12 Months Ended
Jun. 30, 2020
Dec. 31, 2019
Gross Sales [Member]    
Concentration Risk [Line Items]    
Number of customers 2  
Concentration risk percentage 39.00%  
Accounts Receivable [Member]    
Concentration Risk [Line Items]    
Number of customers 2 1
Concentration risk percentage 71.00% 44.00%