Income Taxes (Interest and Penalties Related to Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Line Items]
Accrued interest and penalties	$ 122	$ 338
Net after-tax interest and penalties tax benefit (expense)	9	41	$ (3)
Southern California Edison
Income Tax Disclosure [Line Items]
Accrued interest and penalties	40	64
Net after-tax interest and penalties tax benefit (expense)	$ 14	$ 16	$ 2