Utility Plant and Nonutility Property - Property, Plant and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Generation [Member]
Property Plant And Equipment [Line Items]
Utility plant in service	$ 6,322	$ 6,108
Transmission [Member]
Property Plant And Equipment [Line Items]
Utility plant in service	2,272	2,145
Distribution [Member]
Property Plant And Equipment [Line Items]
Utility plant in service	5,901	5,472
Storage [Member]
Property Plant And Equipment [Line Items]
Utility plant in service	79	76
General and other
Property Plant And Equipment [Line Items]
Utility plant in service	644	630
Intangible
Property Plant And Equipment [Line Items]
Utility plant in service	282	257
Construction Work In Progress
Property Plant And Equipment [Line Items]
Utility plant in service	606	541
Nuclear Fuel
Property Plant And Equipment [Line Items]
Utility plant in service	609	550
Total Gross Utility Plant
Property Plant And Equipment [Line Items]
Utility plant in service	16,715	15,779
Gross Nonutility Property
Property Plant And Equipment [Line Items]
Gross nonutility property	$ 25	$ 21