Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Narrative (Details)

v3.19.2
Summary of Significant Accounting Policies - Narrative (Details)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2019
USD ($)
Jun. 30, 2018
USD ($)
Jun. 30, 2019
USD ($)
BusinessActivity
Segment
Jun. 30, 2018
USD ($)
Jan. 01, 2019
USD ($)
Summary Of Significant Accounting Policies [Line Items]          
Number of operating segments | Segment     1    
Number of business activities | BusinessActivity     1    
Deferred revenue, revenue recognized $ 15,500 $ 13,000 $ 29,500 $ 25,800  
Contracted but not yet recognized $ 5,900,000   $ 5,900,000    
Revenue expected to recognize over next twelve months, percent     6.00%    
Revenue recognized, term, existing deferred revenue     10 years    
Deferred revenue, increase (decrease)     $ 112,195 $ 15,190  
Customer agreement, initial term 22 years   22 years    
Customer Agreements, initial set up, discount percent     10.00%    
Cumulative effect of adoption         $ 0
Retained Earnings (Accumulated Deficit)          
Summary Of Significant Accounting Policies [Line Items]          
Cumulative effect of adoption         740
Retained Earnings (Accumulated Deficit) | Accounting Standards Update 2018-02          
Summary Of Significant Accounting Policies [Line Items]          
Cumulative effect of adoption         $ 700
Maximum          
Summary Of Significant Accounting Policies [Line Items]          
Customer agreement, initial term 25 years   25 years    
Minimum          
Summary Of Significant Accounting Policies [Line Items]          
Customer agreement, initial term 20 years   20 years    
Under SREC contracts          
Summary Of Significant Accounting Policies [Line Items]          
Deferred revenue, increase (decrease) $ 95,500        
Under SREC contracts | Maximum          
Summary Of Significant Accounting Policies [Line Items]          
Customer agreement, initial term 15 years   15 years    
Under SREC contracts | Minimum          
Summary Of Significant Accounting Policies [Line Items]          
Customer agreement, initial term 10 years   10 years    
Solar energy systems | Under Customer Agreements          
Summary Of Significant Accounting Policies [Line Items]          
Average age     4 years