Other Investments (Amortized Cost and Fair Value of Nuclear Decommissioning Trusts) (Details) (USD $) In Millions, unless otherwise specified									6 Months Ended		6 Months Ended		6 Months Ended		6 Months Ended		6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 Southern California Edison	Mar. 31, 2013 Southern California Edison	Dec. 31, 2012 Southern California Edison	Jun. 30, 2012 Southern California Edison	Mar. 31, 2012 Southern California Edison	Dec. 31, 2011 Southern California Edison	Jun. 30, 2013 Southern California Edison Stocks	Dec. 31, 2012 Southern California Edison Stocks	Jun. 30, 2013 Southern California Edison Municipal bonds	Dec. 31, 2012 Southern California Edison Municipal bonds	Jun. 30, 2013 Southern California Edison U.S. government and agency securities	Dec. 31, 2012 Southern California Edison U.S. government and agency securities	Jun. 30, 2013 Southern California Edison Corporate bonds	Dec. 31, 2012 Southern California Edison Corporate bonds	Jun. 30, 2013 Southern California Edison Short-term investments and receivables/payables	Dec. 31, 2012 Southern California Edison Short-term investments and receivables/payables
Nuclear Decommissioning Trusts Disclosures
Longest Maturity Dates (in years)									0		2051		2043		2054		One-year
Total Investments, Amortized Cost			$ 2,774		$ 2,484				$ 728	$ 978	$ 504	$ 518	$ 975	$ 547	$ 293	$ 324	$ 274	$ 117
Total Investments, Fair Value			4,329		4,049				2,085	2,271	592	644	1,025	603	347	410	280	121
Net payables	(148)	(1)	(148)			(1)
Total Nuclear Decommissioning Trusts, Amortized Cost			2,626		2,483
Total Nuclear Decommissioning Trusts, Fair Value	$ 4,181	$ 4,048	$ 4,181	$ 4,246	$ 4,048	$ 3,810	$ 3,853	$ 3,592