Selected Balance Sheet Data, Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions		Sep. 30, 2022	Dec. 31, 2021
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 64,685	$ 62,209
Less accumulated depreciation and amortization		(17,639)	(17,060)
Property, plant and equipment, net		47,287	45,457
Electric plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		48,959	48,680
Natural gas plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		8,199	7,758
Common and other property
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		2,824	2,602
Plant to be retired
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	[1]	2,258	1,200
Construction work in progress
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		2,445	1,969
Nuclear fuel
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		3,105	3,081
Less accumulated depreciation and amortization		$ (2,864)	$ (2,773)

[1] Amounts as of Dec. 31, 2021 include Sherco Units 1, 2 and 3 and A.S. King for NSP-Minnesota; Comanche Unit 1 and 2 and Craig Units 1 and 2 for PSCo; and Tolk and coal generation assets at Harrington pending facility gas conversion for SPS. Following the June 2022 approval of PSCo’s revised resource plan settlement, amounts as of Sept. 30, 2022 include the addition of Comanche Unit 3, Hayden Units 1 and 2 and coal generation assets at Pawnee pending facility gas conversion. Amounts are presented net of accumulated depreciation.