Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023		Dec. 31, 2022
One C&I Customer | Customer Concentration Risk | Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage		10.60%
Regulated Electric | Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	$ 1,461	$ 1,594		$ 1,598
Regulated Electric | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	413	442		445
Regulated Electric | Retail | Commercial and Industrial Customers [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,000	1,094	[1]	1,102
Regulated Electric | Retail | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	48	58		51
Regulated Electric | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	116	223		407
Regulated Electric | Transmission
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	288	296		296
Regulated Electric | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	5	0		10
Regulated Electric | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,870	2,113		2,311
Regulated Electric | Alternative revenue and other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	69	39		115
Total revenues | Regulated Electric
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,939	$ 2,152		$ 2,426

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