v3.26.1
Fair Value - Schedule of Recurring Fair Value Measurements (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Assets    
Cash equivalents $ 9 $ 16
Equity securities 1,196 1,105
Debt securities 786 777
Receivables (payables), net 6 2
NDT funds 1,997 1,900
Derivative assets, netting (893) (396)
Total assets 2,137 1,960
Liabilities    
Derivative liabilities, netting (972) (440)
Total liabilities 723 168
Commodity derivatives    
Assets    
Derivative assets, netting (893) (396)
Derivative assets, total 137 60
Liabilities    
Derivative liabilities, netting (972) (440)
Derivative liabilities, total 721 156
Interest rate derivatives    
Assets    
Derivative assets, total 3 0
Liabilities    
Derivative liabilities, total 2 12
U.S. government debt securities    
Assets    
Debt securities 368 399
Municipal debt securities    
Assets    
Debt securities 94 101
Corporate debt securities    
Assets    
Debt securities 324 277
Level 1    
Assets    
Cash equivalents 0 0
Equity securities 961 871
NDT funds 1,213 1,168
Total assets 2,103 1,529
Liabilities    
Total liabilities 950 407
Level 1 | Commodity derivatives    
Assets    
Derivative assets 890 361
Liabilities    
Derivative liabilities 950 407
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 252 297
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 534 480
Total assets 677 575
Liabilities    
Total liabilities 745 201
Level 2 | Commodity derivatives    
Assets    
Derivative assets 140 95
Liabilities    
Derivative liabilities 743 189
Level 2 | Interest rate derivatives    
Assets    
Derivative assets, total 3 0
Liabilities    
Derivative liabilities 2 12
Level 2 | U.S. government debt securities    
Assets    
Debt securities 116 102
Level 2 | Municipal debt securities    
Assets    
Debt securities 94 101
Level 2 | Corporate debt securities    
Assets    
Debt securities 324 277
NAV    
Assets    
Cash equivalents 9 16
Equity securities 235 234
NDT funds 244 250
Total assets 244 250
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