Selected Balance Sheet Data, Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions		Jun. 30, 2020	Dec. 31, 2019
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 57,897	$ 55,844
Less accumulated depreciation and amortization		(17,097)	(16,735)
Property, plant and equipment, net		41,124	39,483
Electric plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		45,413	44,355
Natural gas plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		6,747	6,560
Common and other property
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		2,385	2,341
Plant to be retired
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	[1]	292	259
CWIP
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		3,060	2,329
Nuclear fuel
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		2,925	2,909
Less accumulated depreciation and amortization		$ (2,601)	$ (2,535)

[1] In 2018, the CPUC approved early retirement of PSCo’s Comanche Units 1 and 2 in approximately 2022 and 2025, respectively. PSCo also expects Craig Unit 1 to be retired early in 2025. Amounts are presented net of accumulated depreciation.