Variable Interest Entities (Details) (Southern California Edison, USD $)	3 Months Ended		6 Months Ended				1 Months Ended						3 Months Ended	6 Months Ended		1 Months Ended		3 Months Ended			3 Months Ended		6 Months Ended
	Jun. 30, 2013 SCE Trust I	Jun. 30, 2012 SCE Trust I	Jun. 30, 2013 SCE Trust I	Jun. 30, 2012 SCE Trust I	Dec. 31, 2012 SCE Trust I	May 31, 2012 SCE Trust I	May 31, 2012 SCE Trust I Trust Securities	Jun. 30, 2013 SCE Trust I Trust Securities	Dec. 31, 2012 SCE Trust I Trust Securities	Jun. 30, 2013 SCE Trust I Series F Preferred Stock	Dec. 31, 2012 SCE Trust I Series F Preferred Stock	May 31, 2012 SCE Trust I Series F Preferred Stock	Jun. 30, 2013 SCE Trust II	Jun. 30, 2013 SCE Trust II	Jan. 31, 2013 SCE Trust II	Jan. 31, 2013 SCE Trust II Trust Securities	Jun. 30, 2013 SCE Trust II Trust Securities	Mar. 31, 2013 SCE Trust II Series G Preferred Stock	Jun. 30, 2013 SCE Trust II Series G Preferred Stock	Jan. 31, 2013 SCE Trust II Series G Preferred Stock	Jun. 30, 2013 Variable Interest Entity, Not Primary Beneficiary SCE Power Purchase Contracts MW	Jun. 30, 2012 Variable Interest Entity, Not Primary Beneficiary SCE Power Purchase Contracts MW	Jun. 30, 2013 Variable Interest Entity, Not Primary Beneficiary SCE Power Purchase Contracts MW	Jun. 30, 2012 Variable Interest Entity, Not Primary Beneficiary SCE Power Purchase Contracts MW
Details of projects or entities
Power generating capacity (in megawatts)																					4,057	2,014	4,057	2,014
Payments to unconsolidated VIEs for power purchase contracts																					$ 99,000,000	$ 57,000,000	$ 197,000,000	$ 134,000,000
Future power generating capacity (in megawatts)																					1,358		1,358
Unconsolidated Trust
Liquidation preference							475,000,000									400,000,000
Security dividend rate, (as a percent)							5.625%									5.10%		5.10%
Liquidation value (in dollars per share)							$ 25					$ 2,500				$ 25		$ 2,500		$ 2,500
Common stock	10,000		10,000		10,000	10,000							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	475,000,000	475,000,000					400,000,000		400,000,000	400,000,000
Dividend income and distributions	$ 6,000,000	$ 3,000,000	$ 13,000,000	$ 3,000,000									$ 5,000,000	$ 9,000,000