Property, Plant and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Accumulated depreciation	$ (8,548)	$ (8,132)
Total utility property, plant and equipment	34,945	32,859
Southern California Edison
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Transmission	11,592	10,391
Distribution	20,871	19,255
Generation	3,138	2,986
General plant and other	4,543	4,889
Accumulated depreciation	(8,548)	(8,132)
Total utility property, plant and equipment, Gross	31,596	29,389
Construction work in progress	3,218	3,339
Nuclear fuel, at amortized cost	131	131
Total utility property, plant and equipment	34,945	32,859
Nuclear Fuel (at amortized cost)	131	$ 131
Southern California Edison | Eldorado
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Nuclear fuel, at amortized cost	0
Plant in Service	186
Construction Work in Progress	38
Accumulated Depreciation	20
Nuclear Fuel (at amortized cost)	0
Net Book Value	$ 204
Ownership Interest	59.00%
Southern California Edison | Pacific Intertie
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Nuclear fuel, at amortized cost	$ 0
Plant in Service	191
Construction Work in Progress	11
Accumulated Depreciation	79
Nuclear Fuel (at amortized cost)	0
Net Book Value	$ 123
Ownership Interest	50.00%
Southern California Edison | Palo Verde (nuclear)
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Nuclear fuel, at amortized cost	$ 131
Plant in Service	1,928
Construction Work in Progress	62
Accumulated Depreciation	1,538
Nuclear Fuel (at amortized cost)	131
Net Book Value	$ 583
Ownership Interest	16.00%
Southern California Edison | Total
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Nuclear fuel, at amortized cost	$ 131
Plant in Service	2,305
Construction Work in Progress	111
Accumulated Depreciation	1,637
Nuclear Fuel (at amortized cost)	131
Net Book Value	$ 910