Summary of Significant Accounting Policies (Deferred Financing Costs) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Southern California Edison
Amortization of deferred financing costs charged to interest expense	$ 32	$ 32	$ 29
Edison International
Amortization of deferred financing costs charged to interest expense	$ 36	$ 33	$ 30