Selected Balance Sheet Data, Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions		Mar. 31, 2024	Dec. 31, 2023
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 71,165	$ 69,692
Less accumulated depreciation and amortization		(18,771)	(18,399)
Property, plant and equipment, net		52,765	51,642
Electric plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		52,982	52,494
Natural gas plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		9,198	9,080
Common and other property
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		3,216	3,190
Plant to be retired
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	[1]	1,996	2,055
Construction work in progress
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		3,773	2,873
Nuclear fuel
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		3,379	3,337
Less accumulated depreciation and amortization		$ (3,008)	$ (2,988)

[1] Amounts include Sherco 1 and 3 and A.S. King for NSP-Minnesota; Comanche Units 2 and 3, Craig Units 1 and 2, Hayden Units 1 and 2 and coal generation assets at Pawnee pending facility gas conversion for PSCo; and Tolk Unit 1 and 2 and coal generation assets at Harrington pending facility gas conversion for SPS. Amounts are presented net of accumulated depreciation.