Annual report pursuant to Section 13 and 15(d)

Business Acquisitions and Related Transactions - Additional Information (Details)

v3.20.4
Business Acquisitions and Related Transactions - Additional Information (Details) - USD ($)
 1 Months Ended 12 Months Ended
Jan. 31, 2019
Dec. 31, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Aug. 31, 2018
Business Acquisition [Line Items]            
Fair value of consideration     $ 1,251,000 $ 8,519,000    
Initial cash payment     0 2,460,000    
Measurement period adjustment, recorded as a reduction to goodwill       630,000    
Contingent consideration     0 6,059,000    
Massachusetts Based Solar Operations And Maintenance Firm            
Business Acquisition [Line Items]            
Fair value of consideration $ 1,294,000          
Undisclosed Name of Acquiree One            
Business Acquisition [Line Items]            
Fair value of consideration   $ 425,000        
Initial cash payment   1,901,000        
Debt assumed   0        
Measurement period adjustment, recorded as a reduction to goodwill       628,000 $ 197,000  
Measurement period adjustment, reduction in hold back contingency       398,000    
Undisclosed Name of Acquiree Two            
Business Acquisition [Line Items]            
Initial cash payment         1,691,000  
Debt assumed         0  
Contingent consideration   2,000,000     $ 2,000,000  
Contingent consideration, liability, revenue targets, period         5 years  
Contingent consideration, liability, fair value   $ 555,000 $ 678,000 $ 678,000 $ 555,000 $ 555,000