v3.26.1
Goodwill and Identifiable Intangible Assets and Liabilities - Schedule of Identifiable Intangible Assets and Liabilities Reported in the Balance Sheet (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Finite-Lived and Indefinite-Lived Intangible [Line Items]    
Gross Carrying Amount $ 3,788 $ 3,844
Accumulated Amortization 2,843 2,750
Net 945 1,094
Total identifiable intangible assets 2,286 2,435
Total identifiable intangible liabilities 123 138
Retail trade names (not subject to amortization)    
Finite-Lived and Indefinite-Lived Intangible [Line Items]    
Retail trade names (not subject to amortization) 1,341 1,341
Retail customer relationships    
Finite-Lived and Indefinite-Lived Intangible [Line Items]    
Gross Carrying Amount 2,173 2,173
Accumulated Amortization 2,084 2,067
Net 89 106
Software and other technology-related assets    
Finite-Lived and Indefinite-Lived Intangible [Line Items]    
Gross Carrying Amount 706 656
Accumulated Amortization 401 365
Net 305 291
Retail and wholesale contracts    
Finite-Lived and Indefinite-Lived Intangible [Line Items]    
Gross Carrying Amount 369 369
Accumulated Amortization 333 295
Net 36 74
Long-term service agreements    
Finite-Lived and Indefinite-Lived Intangible [Line Items]    
Gross Carrying Amount 18 18
Accumulated Amortization 6 6
Net 12 12
Total identifiable intangible liabilities 90 100
Other identifiable intangible assets    
Finite-Lived and Indefinite-Lived Intangible [Line Items]    
Gross Carrying Amount 522 628
Accumulated Amortization 19 17
Net 503 611
Wholesale power and fuel purchase contracts    
Finite-Lived and Indefinite-Lived Intangible [Line Items]    
Total identifiable intangible liabilities $ 33 $ 38