Income Taxes (Rate Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Tax Disclosure [Line Items]
Statutory tax rate (as a percent)			21.00%
Income from operations before income taxes	$ 429	$ 352	$ 683	$ 481
Provision for income tax at federal statutory rate of 21%	90	74	143	101
Increase in income tax from:
State tax, net of federal benefit	18	6	11	(7)
Property-related	(43)	(69)	(126)	(147)
Change related to uncertain tax position				(15)
Other	3	(7)	4	(12)
Total income tax expense (benefit)	$ 68	$ 4	$ 32	$ (80)
Effective tax rate (as a percent)	15.90%	1.10%	4.70%	(16.60%)
SCE
Income Tax Disclosure [Line Items]
Statutory tax rate (as a percent)			21.00%
Income from operations before income taxes	$ 461	$ 437	$ 760	$ 611
Provision for income tax at federal statutory rate of 21%	97	92	160	129
Increase in income tax from:
State tax, net of federal benefit	19	11	15	(1)
Property-related	(43)	(69)	(126)	(147)
Change related to uncertain tax position		(1)		(18)
Other	3	(7)	3	(12)
Total income tax expense (benefit)	$ 76	$ 26	$ 52	$ (49)
Effective tax rate (as a percent)	16.50%	5.90%	6.80%	(8.00%)