Derivative Instruments (Balance Sheet Disclosures) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	$ 102		$ 122
Long-Term, Derivative Assets	219		251
Short-Term, Derivative Liabilities	196		152
Long-Term, Derivative Liabilities	1,052		1,042
Southern California Edison
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	102		122
Long-Term, Derivative Assets	219		251
Short-Term, Derivative Liabilities	196		152
Long-Term, Derivative Liabilities	1,052		1,042
Southern California Edison | Electric Utility
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	102		122
Long-Term, Derivative Assets	219		251
Derivative Assets, Total	321		373
Short-Term, Derivative Liabilities	196		152
Long-Term, Derivative Liabilities	1,052		1,042
Derivative Liabilities, Total	1,248		1,194
Net Liability	927		821
Southern California Edison | Electric Utility | Gross amounts recognized
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	104		141
Long-Term, Derivative Assets	219		251
Derivative Assets, Total	323		392
Short-Term, Derivative Liabilities	259		178
Long-Term, Derivative Liabilities	1,052		1,045
Derivative Liabilities, Total	1,311		1,223
Net Liability	988		831
Southern California Edison | Electric Utility | Gross amounts offset in consolidated balance sheets
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	(2)		(19)
Long-Term, Derivative Assets	0		0
Derivative Assets, Total	(2)		(19)
Short-Term, Derivative Liabilities	(2)		(19)
Long-Term, Derivative Liabilities	0		0
Derivative Liabilities, Total	(2)		(19)
Net Liability	0		0
Southern California Edison | Electric Utility | Cash collateral posted
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	0	[1]	0	[1]
Long-Term, Derivative Assets	0	[1]	0	[1]
Derivative Assets, Total	0	[1]	0	[1]
Short-Term, Derivative Liabilities	(61)	[1]	(7)	[1]
Long-Term, Derivative Liabilities	0	[1]	(3)	[1]
Derivative Liabilities, Total	(61)	[1]	(10)	[1]
Net Liability	$ (61)	[1]	$ (10)	[1]

[1] In addition, at December 31, 2014 and 2013, SCE had posted $36 million and $19 million, respectively, of collateral that is not offset against derivative liabilities and is reflected in "Other current assets" on the consolidated balance sheets.