Other Investments (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Nuclear Decommissioning Trusts Disclosures
Amortized Cost	$ 2,256,000,000		$ 2,256,000,000		$ 2,185,000,000
Fair Value	3,657,000,000	3,083,000,000	3,657,000,000	3,083,000,000	3,480,000,000
Proceeds from sale of securities	524,000,000	315,000,000	1,146,000,000	600,000,000
Unrealized Holding Gains Net of Losses on Investments in Trust			1,400,000,000		1,300,000,000
Summary of changes in the fair value of the trust
Balance at beginning of period	3,619,000,000	3,248,000,000	3,480,000,000	3,140,000,000	3,140,000,000
Realized gains - net	12,000,000	13,000,000	35,000,000	34,000,000
Unrealized gains (losses) - net	4,000,000	(205,000,000)	106,000,000	(143,000,000)
Other-than-temporary impairments	(4,000,000)	(7,000,000)	(13,000,000)	(11,000,000)
Interest, dividends, contributions and other	26,000,000	34,000,000	49,000,000	63,000,000
Balance at end of period	3,657,000,000	3,083,000,000	3,657,000,000	3,083,000,000	3,480,000,000
Southern California Edison Company
Fair Value Disclosures:
Contributions received for decommissioning trusts			23,000,000
Period of reviewing contributions from decommissioning trusts (in years)			3Y
Stocks
Nuclear Decommissioning Trusts Disclosures
Amortized Cost	862,000,000		862,000,000		895,000,000
Fair Value	2,062,000,000		2,062,000,000		2,029,000,000
Summary of changes in the fair value of the trust
Balance at end of period	2,062,000,000		2,062,000,000		2,029,000,000
Municipal bonds
Nuclear Decommissioning Trusts Disclosures
Longest maturity dates decommissioning trust investments			2050
Amortized Cost	699,000,000		699,000,000		706,000,000
Fair Value	812,000,000		812,000,000
Summary of changes in the fair value of the trust
Balance at beginning of period			790,000,000
Balance at end of period	812,000,000		812,000,000
U.S. government and agency securities
Nuclear Decommissioning Trusts Disclosures
Longest maturity dates decommissioning trust investments			2041
Amortized Cost	396,000,000		396,000,000		270,000,000
Fair Value	427,000,000		427,000,000
Summary of changes in the fair value of the trust
Balance at beginning of period			288,000,000
Balance at end of period	427,000,000		427,000,000
Corporate bonds
Nuclear Decommissioning Trusts Disclosures
Longest maturity dates decommissioning trust investments			2054
Amortized Cost	255,000,000		255,000,000		288,000,000
Fair Value	310,000,000		310,000,000
Summary of changes in the fair value of the trust
Balance at beginning of period			346,000,000
Balance at end of period	310,000,000		310,000,000
Short-term investments, primarily cash equivalents
Nuclear Decommissioning Trusts Disclosures
Longest maturity dates decommissioning trust investments			One-year
Amortized Cost	44,000,000		44,000,000		26,000,000
Fair Value	46,000,000		46,000,000
Summary of changes in the fair value of the trust
Balance at beginning of period			27,000,000
Balance at end of period	$ 46,000,000		$ 46,000,000