Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
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	$ 1,712	$ 1,461	$ 1,594
Regulated Electric | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	453	413	442
Regulated Electric | Retail | Commercial and Industrial Customers [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,209	1,000	1,094	[1]
Regulated Electric | Retail | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	50	48	58
Regulated Electric | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	111	116	223
Regulated Electric | Transmission
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	316	288	296
Regulated Electric | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	4	5	0
Regulated Electric | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	2,143	1,870	2,113
Regulated Electric | Alternative revenue and other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	37	69	39
Total revenues | Regulated Electric
Disaggregation of Revenue [Line Items]
Total revenues	$ 2,180	$ 1,939	$ 2,152

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