Other Investments (Textual) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Other Investments [Line Items]
Proceeds from sale of securities	$ 2,853,000,000	$ 1,502,000,000
Southern California Edison
Other Investments [Line Items]
Proceeds from sale of securities	2,853,000,000	1,502,000,000
Unrealized holding gains, net of losses	1,800,000,000		1,800,000,000
Deferred income taxes related to unrealized gains	448,000,000
Nuclear decommissioning trusts	$ 4,400,000,000