Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Deferred Revenue (Details)

v3.20.2
Summary of Significant Accounting Policies - Deferred Revenue (Details) - USD ($)
$ in Thousands
Sep. 30, 2020
Dec. 31, 2019
Dec. 31, 2018
Deferred Revenue Arrangement [Line Items]      
Deferred revenue $ 744,961 $ 729,499 $ 591,600
Customer agreements      
Deferred Revenue Arrangement [Line Items]      
Deferred revenue 613,120 603,504  
Customer agreements | Payments received, net      
Deferred Revenue Arrangement [Line Items]      
Deferred revenue 562,996 558,630  
Customer agreements | Financing component balance      
Deferred Revenue Arrangement [Line Items]      
Deferred revenue 50,124 44,874  
SREC contracts      
Deferred Revenue Arrangement [Line Items]      
Deferred revenue 131,841 125,995  
SREC contracts | Payments received, net      
Deferred Revenue Arrangement [Line Items]      
Deferred revenue 126,806 122,680  
SREC contracts | Financing component balance      
Deferred Revenue Arrangement [Line Items]      
Deferred revenue $ 5,035 $ 3,315