Derivative Instruments (Balance Sheet Disclosures) (Details) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Fair Value of Derivative Instruments
Short-Term, Derivative Assets		$ 79	$ 102
Long-Term, Derivative Assets		84	219
Short-Term, Derivative Liabilities		218	196
Long-Term, Derivative Liabilities		1,100	1,052
Southern California Edison
Fair Value of Derivative Instruments
Short-Term, Derivative Assets		79	102
Long-Term, Derivative Assets		84	219
Short-Term, Derivative Liabilities		218	196
Long-Term, Derivative Liabilities		1,100	1,052
Southern California Edison | Electric Utility
Fair Value of Derivative Instruments
Short-Term, Derivative Assets		79	102
Long-Term, Derivative Assets		84	219
Derivative Assets, Total		163	321
Short-Term, Derivative Liabilities		218	196
Long-Term, Derivative Liabilities		1,100	1,052
Derivative Liabilities, Total		1,318	1,248
Net Liability		1,155	927
Southern California Edison | Electric Utility | Gross amounts recognized
Fair Value of Derivative Instruments
Short-Term, Derivative Assets		81	104
Long-Term, Derivative Assets		84	219
Derivative Assets, Total		165	323
Short-Term, Derivative Liabilities		235	259
Long-Term, Derivative Liabilities		1,100	1,052
Derivative Liabilities, Total		1,335	1,311
Net Liability		1,170	988
Southern California Edison | Electric Utility | Gross amounts offset in consolidated balance sheets
Fair Value of Derivative Instruments
Short-Term, Derivative Assets		(2)	(2)
Long-Term, Derivative Assets		0	0
Derivative Assets, Total		(2)	(2)
Short-Term, Derivative Liabilities		(2)	(2)
Long-Term, Derivative Liabilities		0	0
Derivative Liabilities, Total		(2)	(2)
Net Liability		0	0
Southern California Edison | Electric Utility | Cash collateral posted
Fair Value of Derivative Instruments
Short-Term, Derivative Assets	[1]	0	0
Long-Term, Derivative Assets	[1]	0	0
Derivative Assets, Total	[1]	0	0
Short-Term, Derivative Liabilities	[1]	(15)	(61)
Long-Term, Derivative Liabilities	[1]	0	0
Derivative Liabilities, Total	[1]	(15)	(61)
Net Liability	[1]	$ (15)	$ (61)

[1] In addition, at December 31, 2015 and 2014, SCE had posted $31 million and $36 million, respectively, of collateral that is not offset against derivative liabilities and is reflected in "Other current assets" on the consolidated balance sheets.