Other Investments (Summary of Changes in Fair Value of the Nuclear Decommissioning Trusts) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Summary Of Changes In The Fair Value [Roll Forward]
Balance at end of period	$ 4,494	$ 4,048
Southern California Edison
Summary Of Changes In The Fair Value [Roll Forward]
Balance at beginning of period	4,048	3,592	3,480
Gross realized gains	300	73	108
Gross realized losses	(32)	(5)	(17)
Unrealized gains (losses), net	160	276	(7)
Other-than-temporary impairments	(47)	(36)	(47)
Interest, dividends, contributions and other	65	148	75
Balance at end of period	$ 4,494	$ 4,048	$ 3,592