Property, Plant and Equipment, Net - SPPC (Details) - SPPC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Construction work-in-progress	$ 355	$ 326
Property, plant and equipment, net	3,883	3,822
Regulated
Property, Plant and Equipment [Line Items]
Utility plant in-service	5,651	5,587
Accumulated depreciation and amortization	(2,123)	(2,091)
Plant, net	3,528	3,496
Regulated | Generation
Property, Plant and Equipment [Line Items]
Generation	1,314	1,313
Transmission	1,043	1,023
Distribution	2,109	2,074
Intangible plant and other	$ 249	247
Regulated | Generation | Minimum
Property, Plant and Equipment [Line Items]
Useful life, generation	25 years
Useful life, transmission	50 years
Useful life, distribution	20 years
Useful life, other	5 years
Regulated | Generation | Maximum
Property, Plant and Equipment [Line Items]
Useful life, generation	70 years
Useful life, transmission	76 years
Useful life, distribution	76 years
Useful life, other	65 years
Regulated | Natural Gas Processing Plant
Property, Plant and Equipment [Line Items]
Distribution	$ 541	537
Intangible plant and other	$ 17	17
Regulated | Natural Gas Processing Plant | Minimum
Property, Plant and Equipment [Line Items]
Useful life, distribution	35 years
Useful life, other	5 years
Regulated | Natural Gas Processing Plant | Maximum
Property, Plant and Equipment [Line Items]
Useful life, distribution	70 years
Useful life, other	65 years
Regulated | Common Facilities
Property, Plant and Equipment [Line Items]
Common other	$ 378	$ 376
Regulated | Common Facilities | Minimum
Property, Plant and Equipment [Line Items]
Useful life, common general	5 years
Regulated | Common Facilities | Maximum
Property, Plant and Equipment [Line Items]
Useful life, common general	65 years