Selected Balance Sheet Data Balance Sheet Related Disclosures, Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions		Mar. 31, 2023	Dec. 31, 2022
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 10,753	$ 10,615
Accumulated depreciation		(2,543)	(2,486)
Property, plant and equipment, net		8,210	8,129
Electric plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		10,254	10,182
Plant to be Retired
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	[1]	260	266
Construction work in progress
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 239	$ 167

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