Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Investments in Affiliates and Other Entities (Details)

v3.21.2
Summary of Significant Accounting Policies - Investments in Affiliates and Other Entities (Details)
mile in Thousands, $ in Thousands
 1 Months Ended 3 Months Ended 9 Months Ended
Oct. 31, 2021
USD ($)
Sep. 30, 2021
USD ($)
Sep. 30, 2020
USD ($)
Jun. 30, 2020
USD ($)
mile
Sep. 30, 2021
USD ($)
Sep. 30, 2020
USD ($)
Mar. 31, 2021
USD ($)
Dec. 31, 2020
USD ($)
Summary Of Significant Accounting Policies [Line Items]                
Equity method investments   $ 73,800     $ 73,800     $ 44,900
Equity in earnings (losses) of unconsolidated affiliates   10,758 $ 5,260   24,734 $ (2,207)    
Investment in real estate   23,400     23,400   $ 23,500  
Impairment of cost method investment   0 $ 0   0 9,311    
Length of electric transmission and distribution system | mile       18        
Quanta Services, Inc.                
Summary Of Significant Accounting Policies [Line Items]                
Cost method investments   130,200     130,200     39,500
LUMA Energy, LLC                
Summary Of Significant Accounting Policies [Line Items]                
Term of operation and maintenance agreement       15 years        
Integral Affiliates                
Summary Of Significant Accounting Policies [Line Items]                
Due from related parties   13,300     13,300      
Due to related parties   3,200     3,200      
Certain Non-Integral Equity Investments                
Summary Of Significant Accounting Policies [Line Items]                
Equity in earnings (losses) of unconsolidated affiliates           $ (8,700)    
Broadband Technology Provider                
Summary Of Significant Accounting Policies [Line Items]                
Cost method investments             $ 90,000  
Cost Method Investment | Quanta Services, Inc.                
Summary Of Significant Accounting Policies [Line Items]                
Impairment of cost method investment       $ 9,300        
LUMA Energy, LLC                
Summary Of Significant Accounting Policies [Line Items]                
Equity method investments   $ 34,500     $ 34,500     $ 10,900
Equity interest       50.00%        
Integral Unconsolidated Affiliates | Subsequent Event                
Summary Of Significant Accounting Policies [Line Items]                
Equity interest 44.00%              
Payments to interest in entity $ 18,000