Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Depreciation expense expressed as a percentage of average depreciable property	3.70%	3.50%	3.40%
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	$ 122	$ 106
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	$ 803	631
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	$ 330	289
Public Utilities, Inventory, Fuel [Member]
Inventories	201	182
Public Utilities, Inventory, Natural Gas [Member]
Inventories	$ 272	$ 160