Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Additional Information (Details)

v3.20.4
Summary of Significant Accounting Policies - Additional Information (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
USD ($)
business_activity
reporting_unit
segment
shares
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Jan. 01, 2020
USD ($)
Mar. 31, 2019
Jan. 01, 2019
USD ($)
Jan. 01, 2018
USD ($)
Summary Of Significant Accounting Policies [Line Items]              
Number of operating segments | segment 1            
Number of business activities | business_activity 1            
Bad debt expense $ 7,200 $ 3,400 $ 3,400        
Uncollectible receivables written off 5,400 2,000 2,800        
Capitalized additional costs associated with software $ 2,000 2,600 2,500        
Number of reporting units | reporting_unit 1            
Initial lease term 22 years            
Accumulated other comprehensive income $ (106,755) (52,753)          
Retained earnings $ 76,844 251,466          
Cumulative Effect, Period of Adoption, Adjustment              
Summary Of Significant Accounting Policies [Line Items]              
Accumulated other comprehensive income           $ (700) $ 2,000
Retained earnings       $ (1,200)   $ 700 $ 2,000
Vivant | Common Stock              
Summary Of Significant Accounting Policies [Line Items]              
Common stock issued (in shares) | shares 0.55            
Minimum              
Summary Of Significant Accounting Policies [Line Items]              
Initial lease term 20 years            
Maximum              
Summary Of Significant Accounting Policies [Line Items]              
Initial lease term 25 years            
Solar energy systems              
Summary Of Significant Accounting Policies [Line Items]              
Estimated useful life 35 years            
Inverters              
Summary Of Significant Accounting Policies [Line Items]              
Estimated useful life 10 years            
Under Customer Agreements | Solar energy systems              
Summary Of Significant Accounting Policies [Line Items]              
Residential solar energy system, average age 4 years            
Under SREC contracts | Minimum              
Summary Of Significant Accounting Policies [Line Items]              
Initial lease term         10 years    
Under SREC contracts | Maximum              
Summary Of Significant Accounting Policies [Line Items]              
Initial lease term         15 years    
Solar energy systems and product sales              
Summary Of Significant Accounting Policies [Line Items]              
Costs $ 357,876 365,485 $ 294,066        
Solar energy systems and product sales | Cost of Goods and Service Benchmark | Supplier Concentration Risk | Top Five Suppliers              
Summary Of Significant Accounting Policies [Line Items]              
Costs $ 297,700 $ 180,100