XML 65 R52.htm IDEA: XBRL DOCUMENT v3.20.4
Summary of Significant Accounting Policies - Concentration of Credit Risk (Details)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Minimum      
Concentration Risk [Line Items]      
Customer contracts, term of contracts 3 years    
Maximum      
Concentration Risk [Line Items]      
Customer contracts, term of contracts 5 years    
Top Five Customers | Customer Concentration Risk | Revenue      
Concentration Risk [Line Items]      
Concentration risk, percentage 68.00% 69.20% 69.00%