v3.25.2
Fair Value - Schedule of Recurring Fair Value Measurements (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Assets    
Cash equivalents $ 14 $ 3
Equity securities 1,146 1,105
Debt securities 617 611
Receivables (payables), net 13 5
NDT funds 1,790 1,724
Derivative assets, netting (389) (156)
Total assets 1,870 1,795
Liabilities    
Derivative liabilities, netting (458) (167)
Total liabilities 94 7
Commodity derivatives    
Assets    
Derivative assets, netting (389) (156)
Derivative assets, total 78 69
Liabilities    
Derivative liabilities, netting (458) (167)
Derivative liabilities, total 81 7
Interest rate derivatives    
Assets    
Derivative assets, total 2 2
Liabilities    
Derivative liabilities, total 13 0
U.S. government debt securities    
Assets    
Debt securities 330 353
Municipal debt securities    
Assets    
Debt securities 96 85
Corporate debt securities    
Assets    
Debt securities 191 173
Level 1    
Assets    
Cash equivalents 0 0
Equity securities 786 758
NDT funds 1,116 1,111
Total assets 1,476 1,245
Liabilities    
Total liabilities 429 145
Level 1 | Commodity derivatives    
Assets    
Derivative assets 360 134
Liabilities    
Derivative liabilities 429 145
Level 1 | Interest rate derivatives    
Assets    
Derivative assets, total 0 0
Liabilities    
Derivative liabilities 0 0
Level 1 | U.S. government debt securities    
Assets    
Debt securities 330 353
Level 1 | Municipal debt securities    
Assets    
Debt securities 0 0
Level 1 | Corporate debt securities    
Assets    
Debt securities 0 0
Level 2    
Assets    
Cash equivalents 0 0
Equity securities 0 0
NDT funds 287 258
Total assets 396 351
Liabilities    
Total liabilities 123 29
Level 2 | Commodity derivatives    
Assets    
Derivative assets 107 91
Liabilities    
Derivative liabilities 110 29
Level 2 | Interest rate derivatives    
Assets    
Derivative assets, total 2 2
Liabilities    
Derivative liabilities 13 0
Level 2 | U.S. government debt securities    
Assets    
Debt securities 0 0
Level 2 | Municipal debt securities    
Assets    
Debt securities 96 85
Level 2 | Corporate debt securities    
Assets    
Debt securities 191 173
NAV    
Assets    
Cash equivalents 14 3
Equity securities 360 347
NDT funds 374 350
Total assets 374 350
Liabilities    
Total liabilities 0 0
NAV | Commodity derivatives    
Assets    
Derivative assets 0 0
Liabilities    
Derivative liabilities 0 0
NAV | Interest rate derivatives    
Assets    
Derivative assets, total 0 0
Liabilities    
Derivative liabilities 0 0
NAV | U.S. government debt securities    
Assets    
Debt securities 0 0
NAV | Municipal debt securities    
Assets    
Debt securities 0 0
NAV | Corporate debt securities    
Assets    
Debt securities $ 0 $ 0