Income Taxes (Tax Rate Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Tax Disclosures [Line Items]
Income from operations before income taxes	$ 129	$ 196
Provision for income tax at federal statutory rate of 21%	27	41
Decrease in income tax from:
State tax, net of federal benefit	(13)	(7)
Property-related	(78)	(69)
Change related to uncertain tax position	(15)	0
Deferred tax re-measurement	0	(69)
Other	(5)	(8)
Total income tax benefit	$ (84)	$ (112)
Effective tax rate	(65.10%)	(57.10%)
Southern California Edison
Income Tax Disclosures [Line Items]
Income from operations before income taxes	$ 174	$ 218
Provision for income tax at federal statutory rate of 21%	37	46
Decrease in income tax from:
State tax, net of federal benefit	(12)	(5)
Property-related	(78)	(69)
Change related to uncertain tax position	(17)	0
Deferred tax re-measurement	0	(69)
Other	(5)	(8)
Total income tax benefit	$ (75)	$ (105)
Effective tax rate	(43.10%)	(48.20%)