Derivative Instruments (Balance Sheet Disclosures) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	$ 91		$ 129
Long-Term, Derivative Assets	73		85
Short-Term, Derivative Liabilities	140		126
Long-Term, Derivative Liabilities	1,027		939
Southern California Edison
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	91		129
Long-Term, Derivative Assets	73		85
Short-Term, Derivative Liabilities	140		126
Long-Term, Derivative Liabilities	1,027		939
Southern California Edison | Commodity Contracts | Electric Utility
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	91		129
Long-Term, Derivative Assets	73		85
Derivative Assets, Total	164		214
Short-Term, Derivative Liabilities	140		126
Long-Term, Derivative Liabilities	1,027		939
Derivative Liabilities, Total	1,167		1,065
Net Asset (Liability)	1,003		851
Southern California Edison | Commodity Contracts | Electric Utility | Economic hedges
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	106		151
Long-Term, Derivative Assets	74		91
Derivative Assets, Total	180		242
Short-Term, Derivative Liabilities	170		186
Long-Term, Derivative Liabilities	1,035		954
Derivative Liabilities, Total	1,205		1,140
Net Asset (Liability)	1,025		898
Southern California Edison | Commodity Contracts | Electric Utility | Netting and Collateral
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	(15)		(22)
Long-Term, Derivative Assets	(1)		(6)
Derivative Assets, Total	(16)		(28)
Short-Term, Derivative Liabilities	(15)		(22)
Long-Term, Derivative Liabilities	(1)		(6)
Derivative Liabilities, Total	(16)		(28)
Net Asset (Liability)	0		0
Southern California Edison | Commodity Contracts | 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	(15)	[1]	(38)	[1]
Long-Term, Derivative Liabilities	(7)	[1]	(9)	[1]
Derivative Liabilities, Total	(22)	[1]	(47)	[1]
Net Asset (Liability)	$ (22)	[1]	$ (47)	[1]

[1] In addition, SCE has posted $8 million of collateral that is not offset against the derivative liabilities and is reflected in "Other current assets" on both the June 30, 2013 and December 31, 2012 consolidated balance sheets.