Selected Balance Sheet Data Balance Sheet Related Disclosures, Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions		Jun. 30, 2023	Dec. 31, 2022
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 10,920	$ 10,615
Accumulated depreciation		(2,607)	(2,486)
Property, plant and equipment, net		8,313	8,129
Electric plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		10,451	10,182
Plant to be Retired
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	[1]	254	266
Construction work in progress
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 215	$ 167

[1] Amounts include Tolk and coal generation assets at Harrington pending facility gas conversion. Amounts are reported net of accumulated depreciation.