Income Taxes (Tax Rate Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Tax Disclosures [Line Items]
Income from continuing operations before income taxes	$ 289	$ 335	$ 500	$ 687
Provision for income tax at federal statutory rate of 21% and 35%, respectively 1	61	117	105	241
Increase in income tax from:
State tax, net of federal benefit	0	6	(5)	16
Property-related	(69)	(83)	(138)	(196)
Change related to uncertain tax positions	0	(6)	0	(18)
Shared-based compensation	0	(3)	0	(46)
Other	(1)	(5)	(2)	(11)
Total income tax (benefit) expense from continuing operations	$ (9)	$ 26	$ (40)	$ (14)
Effective tax rate	(3.10%)	7.80%	(8.00%)	(2.00%)
State
Increase in income tax from:
Shared-based compensation		$ 4		$ 10
Southern California Edison
Income Tax Disclosures [Line Items]
Income from continuing operations before income taxes	$ 325	395	$ 635	787
Provision for income tax at federal statutory rate of 21% and 35%, respectively 1	68	138	133	275
Increase in income tax from:
State tax, net of federal benefit	3	9	4	22
Property-related	(69)	(83)	(138)	(196)
Change related to uncertain tax positions	0	0	(1)	(11)
Shared-based compensation	0	(1)	0	(9)
Other	(4)	(6)	(6)	(12)
Tax abandonment loss				39
Total income tax (benefit) expense from continuing operations	$ (2)	$ 57	$ (8)	$ 69
Effective tax rate	(0.60%)	14.40%	(1.30%)	8.80%
Southern California Edison | Federal
Increase in income tax from:
Tax abandonment loss				$ 691
Southern California Edison | State
Increase in income tax from:
Shared-based compensation		$ 1		2
Tax abandonment loss				$ 1,130