Revenue from Contracts with Customers - PAC (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Operating revenue	$ 6,111	$ 6,346
Regulated | Regulated retail electric
Disaggregation of Revenue [Line Items]
Total Customer Revenue	2,714	2,688
Regulated | Regulated wholesale
Disaggregation of Revenue [Line Items]
Total Customer Revenue	118	191
Regulated | Regulated transmission and distribution
Disaggregation of Revenue [Line Items]
Total Customer Revenue	509	516
Regulated | Other customer revenue
Disaggregation of Revenue [Line Items]
Total Customer Revenue	27	34
PAC
Disaggregation of Revenue [Line Items]
Other revenue	5	4
Operating revenue	1,548	1,484
PAC | Regulated
Disaggregation of Revenue [Line Items]
Total Customer Revenue	1,543	1,480
PAC | Regulated | Regulated retail electric
Disaggregation of Revenue [Line Items]
Total Customer Revenue	1,447	1,349
PAC | Regulated | Regulated wholesale
Disaggregation of Revenue [Line Items]
Total Customer Revenue	29	61
PAC | Regulated | Regulated transmission and distribution
Disaggregation of Revenue [Line Items]
Total Customer Revenue	41	38
PAC | Regulated | Other customer revenue
Disaggregation of Revenue [Line Items]
Total Customer Revenue	26	32
PAC | Regulated | Residential | Regulated retail electric
Disaggregation of Revenue [Line Items]
Total Customer Revenue	610	585
PAC | Regulated | Commercial | Regulated retail electric
Disaggregation of Revenue [Line Items]
Total Customer Revenue	472	430
PAC | Regulated | Industrial | Regulated retail electric
Disaggregation of Revenue [Line Items]
Total Customer Revenue	319	290
PAC | Regulated | Other retail | Regulated retail electric
Disaggregation of Revenue [Line Items]
Total Customer Revenue	$ 46	$ 44