Fair Value Measurements (Level 3 Rollforward) (Details) (Southern California Edison, Level 3, USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Southern California Edison | Level 3
Fair Value Disclosures Level 3 [Roll Forward]
Fair value of net asset (liabilities) at beginning of period	$ (805)		$ (791)
Total realized/unrealized gains (losses):
Included in regulatory assets and liabilities	31	[1]	(82)	[1]
Purchases	7		18
Settlements	(6)		(27)
Fair value of net liabilities at end of period	(773)		(882)
Change during the period in unrealized losses related to assets and liabilities held at the end of the period	$ 22		$ (66)

[1] Due to regulatory mechanisms, SCE's realized and unrealized gains and losses are recorded as regulatory assets and liabilities.