Balance Sheet Related Disclosures, Property, Plant and Equipment (Details) - USD ($) $ in Millions		Jun. 30, 2019	Dec. 31, 2018
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 53,545	$ 52,249
Less accumulated depreciation		(16,278)	(15,659)
Property, plant and equipment, net		37,651	36,944
Electric plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		43,006	41,472
Natural gas plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		6,289	6,210
Common and other property
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		2,215	2,154
Plant to be retired
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	[1]	290	322
CWIP
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		1,745	2,091
Nuclear fuel
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		2,859	2,771
Less accumulated depreciation		$ (2,475)	$ (2,417)

[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.