Property, Plant and Equipment, Net - SPPC (Details) - SPPC - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Public Utility, Property, Plant and Equipment [Line Items]
Construction work- in-progress	$ 801	$ 326
Property, plant and equipment, net	$ 4,439	$ 3,822
Depreciation and amortization rate	3.10%	3.30%	3.00%
Regulated assets
Public Utility, Property, Plant and Equipment [Line Items]
Generation	$ 1,339	$ 1,313
Transmission	1,071	1,023
Common other	377	376
Utility plant in-service	5,846	5,587
Accumulated depreciation and amortization	(2,208)	(2,091)
Utility plant in-service, net, excluding construction work-in-process	3,638	3,496
Regulated assets | Electric
Public Utility, Property, Plant and Equipment [Line Items]
Distribution	2,224	2,074
Intangible plant and other	254	247
Regulated assets | Natural gas
Public Utility, Property, Plant and Equipment [Line Items]
Distribution	563	537
Intangible plant and other	$ 18	$ 17
Regulated assets | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Useful life, generation	25 years
Useful life, transmission	50 years
Useful life, common general	5 years
Regulated assets | Minimum | Electric
Public Utility, Property, Plant and Equipment [Line Items]
Useful life, distribution	20 years
Useful life, other	5 years
Regulated assets | Minimum | Natural gas
Public Utility, Property, Plant and Equipment [Line Items]
Useful life, distribution	35 years
Useful life, other	5 years
Regulated assets | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Useful life, generation	70 years
Useful life, transmission	76 years
Useful life, common general	65 years
Regulated assets | Maximum | Electric
Public Utility, Property, Plant and Equipment [Line Items]
Useful life, distribution	76 years
Useful life, other	65 years
Regulated assets | Maximum | Natural gas
Public Utility, Property, Plant and Equipment [Line Items]
Useful life, distribution	70 years
Useful life, other	65 years