v3.26.1
Acquisitions - Narrative (Details)
customer in Thousands, $ in Millions
3 Months Ended 6 Months Ended
Jan. 30, 2026
USD ($)
GW
state
facility
customer
shares
Apr. 10, 2025
USD ($)
facility
MW
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Apr. 14, 2026
USD ($)
Business Combination [Line Items]              
Acquisition-related transaction and integration costs     $ 16 $ 43 $ 61 $ 51  
Senior Notes, due 2034              
Business Combination [Line Items]              
Interest rate % 5.75%            
Lightning Senior Secured Notes, due 2032              
Business Combination [Line Items]              
Debt issuance amount             $ 1,495
LS Power Portfolio              
Business Combination [Line Items]              
Number of gas-fired facilities acquired | facility 18            
States where entity is located | state 9            
Acquisition, shares issued (in shares) | shares 24,250,000            
Cash paid to acquire business $ 6,400            
Acquisition working capital and other adjustments 483            
Proceeds from lines of credit 2,500            
Consideration $ 10,583            
Acquisition-related transaction and integration costs     $ 3 $ 23 $ 41 $ 23  
Blended Federal and state tax rate percentage 24.81%            
LS Power Portfolio | New Secured Notes              
Business Combination [Line Items]              
Proceeds from issuance of senior notes $ 4,400            
LS Power Portfolio | Lightning Senior Secured Notes, due 2032              
Business Combination [Line Items]              
Interest rate % 7.25%            
Debt issuance amount $ 3,200            
LS Power Portfolio | Lightning Senior Secured Notes, due 2032 | Level 2              
Business Combination [Line Items]              
Interest rate % 7.25%            
Debt difference between principal and fair value, amortized through interest expense over remaining term of debt $ 100            
LS Power Portfolio | Natural Gas              
Business Combination [Line Items]              
Number of power generating facilities acquired | GW 13            
LS Power Portfolio | Commercial And industrial Virtual Power Plant Platform              
Business Combination [Line Items]              
Number of customers | customer 2            
Texas Generation Portfolio              
Business Combination [Line Items]              
Number of power generating facilities acquired | facility   6          
Consideration   $ 560          
Generation capacity (in MW) | MW   738          
Working capital adjustments   $ 2