Income Taxes (Interest and Penalties Related to Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Line Items]
Accrued interest and penalties	$ 56	$ 37
Net after-tax interest and penalties tax expense (benefit)	4	(62)	$ 6
SCE
Income Tax Disclosure [Line Items]
Accrued interest and penalties	29	6
Net after-tax interest and penalties tax expense (benefit)	$ 3	$ (25)	$ 4