Revenues (Details) - Regulated Electric - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024		Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 416	$ 487	$ 835		$ 986
Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	458	496	886		1,004
Retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	315	362	627		742
Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	83	91	169		192
Retail | C&I
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	219	257	436	[1]	524
Retail | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	13	14	22		26
Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	30	51	66		96
Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	70	72	141		146
Alternative and Other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	42	9	51		18
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 1	$ 2	$ 1		$ 2

[1] For the six months ended June 30, 2024, revenues from one C&I customer represented approximately 10.2% of total revenues.