XML 85 R61.htm IDEA: XBRL DOCUMENT v3.20.4
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Concentration of Credit Risk) (Details) - Customer Concentration Risk [Member] - numberOfCustomers
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Revenues [Member]      
Concentration Risk [Line Items]      
Number of Customers 1 0 0
Concentration Risk, Benchmark Description 10 10 10
Accounts Receivables [Member]      
Concentration Risk [Line Items]      
Number of Customers 1 0  
Concentration Risk, Benchmark Description 10 10  
Royal Dutch Shell [Member] | Revenues [Member]      
Concentration Risk [Line Items]      
Concentration risk percentage (13.00%)    
Royal Dutch Shell [Member] | Accounts Receivables [Member]      
Concentration Risk [Line Items]      
Concentration risk percentage (16.00%)