Property, Plant and Equipment, Net - NPC (Details) - NPC - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Utility plant in-service, net, excluding construction work-in-process	$ 6,921	$ 6,647
Construction work- in-progress	485	244
Property, plant and equipment, net	$ 7,406	$ 6,891
Depreciation and amortization rate	3.10%	3.20%	3.10%
Regulated assets
Property, Plant and Equipment [Line Items]
Generation	$ 3,977	$ 3,793
Transmission	1,562	1,503
Distribution	4,134	3,920
General and intangible plant	871	836
Utility plant in-service	10,544	10,052
Accumulated depreciation and amortization	(3,624)	(3,406)
Utility plant in-service, net, excluding construction work-in-process	6,920	6,646
Nonregulated assets
Property, Plant and Equipment [Line Items]
Utility plant in-service, net, excluding construction work-in-process	$ 1	$ 1
Useful life, other	45 years
Minimum | Regulated assets
Property, Plant and Equipment [Line Items]
Useful life, generation	30 years
Useful life, transmission	45 years
Useful life, distribution	20 years
Useful life, other	5 years
Maximum | Regulated assets
Property, Plant and Equipment [Line Items]
Useful life, generation	55 years
Useful life, transmission	70 years
Useful life, distribution	65 years
Useful life, other	65 years