Income Taxes (Interest and Penalties Related to Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Line Items]
Accrued interest and penalties	$ 37	$ 115
Net after-tax interest and penalties tax (benefit) expense	(62)	6	$ 6
SCE
Income Tax Disclosure [Line Items]
Accrued interest and penalties	6	41
Net after-tax interest and penalties tax (benefit) expense	$ (25)	$ 4	$ 2