Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Depreciation expense expressed as a percentage of average depreciable property	3.80%	3.60%	3.70%
Nuclear Decommissioning [Abstract]
Studies time periods	3 years
Cash and Cash Equivalents [Abstract]
maturity period	3 months
Accounts, Notes, Loans and Financing Receivable
Allowance for bad debts	$ 111	$ 128
Alternative Revenue Programs [Abstract]
maximum number of months following end of annual period in which revenues are earned to be included in	24 months
Inventories	$ 666	711
Studies time periods	3 years
maximum number of months following end of annual period in which revenues are earned to be included in	24 months
maturity period	3 months
Supplies [Member]
Inventories	$ 406	377
Public Utilities, Inventory, Fuel [Member]
Inventories	164	211
Public Utilities, Inventory, Natural Gas [Member]
Inventories	$ 96	$ 123