v3.26.1
Risk Management - Derivative Liabilities Input Level (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Gross amount $ (284) $ (213)
Energy commodity derivative contracts    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Gross amount (107) (75)
Contracts available for netting 66 68
Cash collateral posted 9  
Cash collateral posted   (2)
Net amount (32) (9)
Energy commodity derivative contracts | Level 1    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Gross amount (4) (12)
Energy commodity derivative contracts | Level 2    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Gross amount (103) (63)
Energy commodity derivative contracts | Level 3    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Gross amount 0 0
Interest rate contracts    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Gross amount (177) (136)
Contracts available for netting 5 6
Cash collateral posted 0 0
Net amount (172) (130)
Interest rate contracts | Level 1    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Gross amount 0 0
Interest rate contracts | Level 2    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Gross amount (177) (136)
Interest rate contracts | Level 3    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Gross amount $ 0 0
Foreign currency contracts    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Gross amount   (2)
Contracts available for netting   0
Cash collateral posted   0
Net amount   (2)
Foreign currency contracts | Level 1    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Gross amount   0
Foreign currency contracts | Level 2    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Gross amount   (2)
Foreign currency contracts | Level 3    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Gross amount   $ 0