Income Taxes (Interest and Penalties Related to Income Taxes) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Line Items]
Accrued interest and penalties	$ 338	$ 406
Net after-tax interest and penalties tax benefit (expense)	41	(3)	(10)
Southern California Edison
Income Tax Disclosure [Line Items]
Accrued interest and penalties	64	88
Net after-tax interest and penalties tax benefit (expense)	$ 16	$ 2	$ (11)