Revenue (Textual) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue from Contract with Customer [Abstract]
Commercial and other non-residential customers implied term			20 years
Southern California Edison
Public Utilities, General Disclosures [Line Items]
Franchise fees billed to customers	$ 47	$ 46	$ 104	$ 103
Rate recovery period			24 months