Other Investments (Textual) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Other Investments [Line Items]
Proceeds from sale of securities	$ 1,502,000,000	$ 435,000,000
Southern California Edison
Other Investments [Line Items]
Contributions received for decommissioning trusts	23,000,000
Proceeds from sale of securities	1,502,000,000	435,000,000
Unrealized holding gains, net of losses	$ 1,790,000,000		$ 1,720,000,000