Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Narrative (Details)

v3.19.3
Summary of Significant Accounting Policies - Narrative (Details)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2019
USD ($)
Mar. 31, 2019
USD ($)
Sep. 30, 2018
USD ($)
Sep. 30, 2019
USD ($)
BusinessActivity
Segment
Sep. 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 $ 15,100   $ 13,300 $ 44,600 $ 39,100  
Contracted but not yet recognized $ 6,200,000     $ 6,200,000    
Revenue expected to recognize over next twelve months, percent       6.00%    
Revenue recognized, term, existing deferred revenue       10 years    
Deferred revenue, increase (decrease)       $ 121,936 $ 21,582  
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        
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