Variable Interest Entities (Details) (Southern California Edison, USD $)	12 Months Ended		1 Months Ended				1 Months Ended	12 Months Ended				1 Months Ended
	Dec. 31, 2012 Series F	Dec. 31, 2012 SCE Trust I	May 31, 2012 SCE Trust I Trust Securities	Dec. 31, 2012 SCE Trust I Trust Securities	Dec. 31, 2012 SCE Trust I Series F	May 31, 2012 SCE Trust I Series F	Jan. 31, 2013 SCE Trust II Trust Securities	Dec. 31, 2012 Variable Interest Entity, Not Primary Beneficiary SCE Power Purchase Contracts MW	Dec. 31, 2011 Variable Interest Entity, Not Primary Beneficiary SCE Power Purchase Contracts	Jan. 31, 2013 Subsequent Event Series G Preferred Stock	Jan. 31, 2013 Subsequent Event SCE Trust II	Jan. 31, 2013 Subsequent Event SCE Trust II Trust Securities	Jan. 31, 2013 Subsequent Event SCE Trust II Series G Preferred Stock
Details of projects or entities
Power generating capacity for majority interest (in megawatts)								2,198
Payments to unconsolidated VIEs for power purchase contracts								$ 397,000,000	$ 477,000,000
Future power generating capacity for majority interest (in megawatts)								3,402
Unconsolidated Trust
Liquidation preference			475,000,000									400,000,000
Security dividend rate, (as a percent)	5.625%		5.625%				5.10%					5.10%
Liquidation value (in dollars per share)			$ 25			$ 2,500				$ 2,500		$ 25	$ 2,500
Common stock		10,000	10,000								10,000
Common stock, percentage issued to Southern California Edison			100.00%								100.00%
Preference stock				475,000,000	475,000,000	475,000,000							400,000,000
Dividend income and distributions		$ 17,000,000