Revenues (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Customer Concentration Risk | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage		10.60%
Regulated Electric | Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers		$ 1,594	$ 1,598	$ 1,255
Regulated Electric | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers		442	445	375
Regulated Electric | Retail | Commercial and Industrial Customers [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	[1]	1,094	1,102	842
Regulated Electric | Retail | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers		58	51	38
Regulated Electric | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers		223	407	873
Regulated Electric | Transmission
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers		296	296	287
Regulated Electric | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers		0	10	6
Regulated Electric | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers		2,113	2,311	2,421
Regulated Electric | Alternative revenue and other
Disaggregation of Revenue [Line Items]
Alternative revenue and other		39	115	44
Total revenues | Regulated Electric
Disaggregation of Revenue [Line Items]
Total revenues		$ 2,152	$ 2,426	$ 2,465

[1] In 2023, revenues from one C&I customer represented approximately 10.6% of total revenues.