Income Taxes (Tax Rate Reconciliation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Line Items]
Income (loss) from continuing operations before income taxes	$ 566	$ 1,127	$ (1,089)
Provision for income tax at federal statutory rate of 21% for 2019 and 2018, and 35% for 2017	119	237	(229)
Increase in income tax from:
State tax, net of federal benefit	(61)	(22)	(168)
Property-related	(320)	(303)	(275)
Change related to uncertain tax positions	(15)	0	(66)
Deferred tax re-measurement	0	(88)	0
2018 GRC Final Decision	0	(80)	0
Corporate-owned life insurance cash surrender value	(8)	(8)	(8)
Other	(20)	(14)	7
Total continuing operations	$ (305)	$ (278)	$ (739)
Effective tax rate	(53.90%)	(24.70%)	(67.90%)
SCE
Income Tax Disclosure [Line Items]
Income (loss) from continuing operations before income taxes	$ 665	$ 1,301	$ (885)
Provision for income tax at federal statutory rate of 21% for 2019 and 2018, and 35% for 2017	140	273	(186)
Increase in income tax from:
State tax, net of federal benefit	(52)	(13)	(155)
Property-related	(320)	(303)	(275)
Change related to uncertain tax positions	(19)	0	(71)
Deferred tax re-measurement	0	(88)	0
2018 GRC Final Decision	0	(80)	0
Corporate-owned life insurance cash surrender value	(8)	(8)	(8)
Other	(18)	(10)	(1)
Total continuing operations	$ (277)	$ (229)	$ (696)
Effective tax rate	(41.70%)	(17.60%)	(78.60%)