Income Taxes (Tax Rate Reconciliation) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Effective Tax Rate
Income from continuing operations before income taxes	$ 384	$ 287
Provision for income tax at federal statutory rate of 35%	134	101
State tax, net of federal benefit	3	6
Property-related	(41)	(10)
Uncertain tax positions	7	1
Other	(5)	(7)
Total income tax expense from continuing operations	98	91
Federal statutory rate (as a percent)	35.00%	35.00%
Effective tax rate	25.50%	31.70%
Southern California Edison
Effective Tax Rate
Income from continuing operations before income taxes	395	300
Provision for income tax at federal statutory rate of 35%	138	105
State tax, net of federal benefit	14	10
Property-related	(42)	(10)
Uncertain tax positions	7	0
Other	(5)	(6)
Total income tax expense from continuing operations	$ 112	$ 99
Federal statutory rate (as a percent)	35.00%	35.00%
Effective tax rate	28.40%	33.00%