v3.26.3
Fair Value - Schedule of Recurring Fair Value Measurements (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Assets    
Cash equivalents $ 0 $ 16
Equity securities 1,052 1,105
Debt securities 904 777
Receivables (payables), net 20 2
NDT funds 1,976 1,900
Derivative assets, netting (894) (396)
Total assets 2,107 1,960
Liabilities    
Derivative liabilities, netting (1,005) (440)
Total liabilities 860 168
Commodity derivatives    
Assets    
Derivative assets, netting (894) (396)
Derivative assets, total 123 60
Liabilities    
Derivative liabilities, netting (1,005) (440)
Derivative liabilities, total 860 156
Interest rate derivatives    
Assets    
Derivative assets, total 8 0
Liabilities    
Derivative liabilities, total 0 12
U.S. government debt securities    
Assets    
Debt securities 423 399
Municipal debt securities    
Assets    
Debt securities 72 101
Corporate debt securities    
Assets    
Debt securities 409 277
Level 1    
Assets    
Cash equivalents 0 0
Equity securities 984 871
NDT funds 1,199 1,168
Total assets 2,074 1,529
Liabilities    
Total liabilities 985 407
Level 1 | Commodity derivatives    
Assets    
Derivative assets 875 361
Liabilities    
Derivative liabilities 985 407
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 215 297
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 689 480
Total assets 839 575
Liabilities    
Total liabilities 880 201
Level 2 | Commodity derivatives    
Assets    
Derivative assets 142 95
Liabilities    
Derivative liabilities 880 189
Level 2 | Interest rate derivatives    
Assets    
Derivative assets, total 8 0
Liabilities    
Derivative liabilities 0 12
Level 2 | U.S. government debt securities    
Assets    
Debt securities 208 102
Level 2 | Municipal debt securities    
Assets    
Debt securities 72 101
Level 2 | Corporate debt securities    
Assets    
Debt securities 409 277
NAV    
Assets    
Cash equivalents 0 16
Equity securities 68 234
NDT funds 68 250
Total assets 68 250
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