Summary of Significant Accounting Policies (Deferred Financing Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Southern California Edison
Amortization of deferred financing costs charged to interest expense	$ 28	$ 32	$ 32
Edison International
Amortization of deferred financing costs charged to interest expense	$ 33	$ 36	$ 33