Other Investments (Summary of Changes in Fair Value of the Nuclear Decommissioning Trusts) (Details) (USD $) In Millions, unless otherwise specified			3 Months Ended		9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Southern California Edison	Sep. 30, 2013 Southern California Edison	Sep. 30, 2014 Southern California Edison	Sep. 30, 2013 Southern California Edison
Summary Of Changes In The Fair Value [Roll Forward]
Balance at beginning of period	$ 4,741	$ 4,494	$ 4,740	$ 4,182	$ 4,494	$ 4,048
Gross realized gains			149	119	187	261
Gross realized losses			0	(17)	0	(18)
Unrealized gains (losses), net			(131)	55	38	46
Other-than-temporary impairments			(4)	(15)	(10)	(44)
Interest, dividends, contributions and other			(13)	8	32	39
Balance at end of period	$ 4,741	$ 4,494	$ 4,741	$ 4,332	$ 4,741	$ 4,332