Derivative Instruments (Balance Sheet Disclosures) (Details) - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	$ 65,000,000	$ 79,000,000
Long-Term, Derivative Assets	78,000,000	84,000,000
Short-Term, Derivative Liabilities	232,000,000	218,000,000
Long-Term, Derivative Liabilities	1,136,000,000	1,100,000,000
Southern California Edison
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	65,000,000	79,000,000
Long-Term, Derivative Assets	78,000,000	84,000,000
Short-Term, Derivative Liabilities	232,000,000	218,000,000
Long-Term, Derivative Liabilities	1,134,000,000	1,100,000,000
Southern California Edison | Electric Utility | Gross amounts recognized
Derivatives
Collateral already posted	12,000,000	0
Southern California Edison | Commodity Contracts | Electric Utility
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	65,000,000	79,000,000
Long-Term, Derivative Assets	78,000,000	84,000,000
Derivative Assets, Total	143,000,000	163,000,000
Short-Term, Derivative Liabilities	232,000,000	218,000,000
Long-Term, Derivative Liabilities	1,134,000,000	1,100,000,000
Derivative Liabilities, Total	1,366,000,000	1,318,000,000
Net Liability	1,223,000,000	1,155,000,000
Southern California Edison | Commodity Contracts | Electric Utility | Gross amounts recognized
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	66,000,000	81,000,000
Long-Term, Derivative Assets	78,000,000	84,000,000
Derivative Assets, Total	144,000,000	165,000,000
Short-Term, Derivative Liabilities	244,000,000	235,000,000
Long-Term, Derivative Liabilities	1,134,000,000	1,100,000,000
Derivative Liabilities, Total	1,378,000,000	1,335,000,000
Net Liability	1,234,000,000	1,170,000,000
Southern California Edison | Commodity Contracts | Electric Utility | Gross amounts offset in the consolidated balance sheets
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	(1,000,000)	(2,000,000)
Long-Term, Derivative Assets	0	0
Derivative Assets, Total	(1,000,000)	(2,000,000)
Short-Term, Derivative Liabilities	(1,000,000)	(2,000,000)
Long-Term, Derivative Liabilities	0	0
Derivative Liabilities, Total	(1,000,000)	(2,000,000)
Net Liability	0	0
Southern California Edison | Commodity Contracts | Electric Utility | Cash collateral posted
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	0	0
Long-Term, Derivative Assets	0	0
Derivative Assets, Total	0	0
Short-Term, Derivative Liabilities	(11,000,000)	(15,000,000)
Long-Term, Derivative Liabilities	0	0
Derivative Liabilities, Total	(11,000,000)	(15,000,000)
Net Liability	(11,000,000)	(15,000,000)
Other current assets | Southern California Edison | Commodity Contracts
Derivatives
Collateral already posted	$ 25,000,000	$ 31,000,000