Income Taxes (Components of Income Tax Expense (Benefit) by Location) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ 13	$ 0	$ (57)
State	(22)	6	(155)
Total current	(9)	6	(212)
Deferred:
Federal	(230)	(243)	(386)
State	(66)	(41)	(141)
Total deferred	(296)	(284)	(527)
Total continuing operations	(305)	(278)	(739)
Discontinued operations	0	0	(34)
Total	(305)	(278)	(773)
SCE
Current:
Federal	12	0	(51)
State	(26)	14	(93)
Total current	(14)	14	(144)
Deferred:
Federal	(207)	(206)	(354)
State	(56)	(37)	(198)
Total deferred	(263)	(243)	(552)
Total continuing operations	(277)	(229)	(696)
Discontinued operations	0	0	0
Total	$ (277)	$ (229)	$ (696)