Regulatory Matters - Regulatory Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Sep. 01, 2023
Regulatory Liabilities [Line Items]
Total regulatory liabilities	$ 7,033	$ 6,818
Other current liabilities
Regulatory Liabilities [Line Items]
Total regulatory liabilities	279	174
Regulatory liabilities
Regulatory Liabilities [Line Items]
Total regulatory liabilities	$ 6,754	6,644
Cost of removal
Regulatory Liabilities [Line Items]
Regulatory liability, amortization period	27 years
Total regulatory liabilities	$ 2,918	2,741
Deferred income taxes
Regulatory Liabilities [Line Items]
Total regulatory liabilities	$ 2,493	2,733	$ 24
Asset retirement obligations
Regulatory Liabilities [Line Items]
Regulatory liability, amortization period	29 years
Total regulatory liabilities	$ 446	364
Employee benefit plans
Regulatory Liabilities [Line Items]
Total regulatory liabilities	292	211
Revenue sharing mechanisms
Regulatory Liabilities [Line Items]
Total regulatory liabilities	$ 263	243
Levelized depreciation
Regulatory Liabilities [Line Items]
Regulatory liability, amortization period	27 years
Total regulatory liabilities	$ 215	230
Other
Regulatory Liabilities [Line Items]
Total regulatory liabilities	$ 406	$ 296