v3.26.3
Summary of Significant Accounting and Reporting Policies - Narrative (Details)
$ in Millions
1 Months Ended 3 Months Ended 9 Months Ended
Aug. 31, 2026
USD ($)
Jul. 31, 2026
jointVenture
Jun. 30, 2026
jointVenture
site
Mar. 31, 2026
USD ($)
jointVenture
site
MW
Dec. 31, 2026
USD ($)
Sep. 30, 2026
USD ($)
jointVenture
Sep. 30, 2026
USD ($)
segment
Sep. 30, 2025
USD ($)
Oct. 31, 2026
USD ($)
Jul. 28, 2026
USD ($)
Dec. 31, 2025
USD ($)
Accounting Policies [Line Items]                      
Cash and Cash Equivalents, Project Level           $ 410 $ 410       $ 334
Restricted cash, current           61 61       62
Tax Credit Carryforward, Amount Sold             (84) $ (4)      
Property, plant and equipment – net           15,090 15,090       15,366
Assets           18,846 18,846       19,595
Investments in equity method investees           $ 661 $ 661       $ 625
Number Of Joint Ventures | jointVenture   2 2 4   2          
Number Of Operating Sites | site     2                
Number of Operating Segments | segment             1        
Number of Reportable Segments | segment             1        
Generation facility capacity (mw) | MW       300              
Gain (Loss) on Disposition of Assets           $ 23          
Gains on disposal of businesses/assets – net             $ 34 $ 9      
Mammoth Plains Energy Storage Company, LLC, And Carousel Energy Storage Project Company, LLC                      
Accounting Policies [Line Items]                      
Investments in equity method investees           $ 13 $ 13        
XPLR OpCo | Joint Venture                      
Accounting Policies [Line Items]                      
Equity Method Investment, Ownership Percentage       49.00%              
NEER Subsidiary | Joint Venture                      
Accounting Policies [Line Items]                      
Equity Method Investment, Ownership Percentage       51.00%              
one operating site | NEER Subsidiary                      
Accounting Policies [Line Items]                      
Number Of Operating Sites | site       1              
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Interconnection Assets and Rights                      
Accounting Policies [Line Items]                      
Consideration $ 16     $ 19              
Gains on disposal of businesses/assets – net $ 10                    
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Interconnection Assets and Rights | Forecast                      
Accounting Policies [Line Items]                      
Gains on disposal of businesses/assets – net         $ 8            
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Assets And Rights At Project Sites                      
Accounting Policies [Line Items]                      
Consideration                   $ 26  
Subsequent Event | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Interconnection Assets and Rights                      
Accounting Policies [Line Items]                      
Consideration                 $ 12    
Gains on disposal of businesses/assets – net         $ 4            
Additional consideration                 $ 4    
XPLR OpCo                      
Accounting Policies [Line Items]                      
Noncontrolling limited partner interest percentage           51.20% 51.20%        
Silver State [Member]                      
Accounting Policies [Line Items]                      
Noncontrolling limited partner interest percentage           50.00% 50.00%        
Sunlight Renewable Holdings                      
Accounting Policies [Line Items]                      
Noncontrolling limited partner interest percentage           33.00% 33.00%        
Star Moon Holdings, LLC                      
Accounting Policies [Line Items]                      
Noncontrolling limited partner interest percentage           50.00% 50.00%        
Emerald Breeze Holdings                      
Accounting Policies [Line Items]                      
Noncontrolling limited partner interest percentage           51.00% 51.00%