Compensation and Benefit Plans (Stock Option Activity) (Details) (Stock Options, USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance (number of options)	19,714,214
Grants (number of options)	3,769,948
Expired (number of options)	(219,983)
Forfeited (number of options)	(223,458)
Exercised (number of options)	(3,808,998)
Ending balance (number of options)	19,231,723
Vested and expected to vest (number of options)	18,958,712
Exercisable (number of options)	10,642,547
Weighted Average Exercise Price [Roll Forward]
Beginning balance, weighted average exercise price (dollars per share)	$ 34.86
Granted, weighted average exercise price (dollars per share)	$ 43.18
Expired, weighted average exercise price (dollars per share)	$ 48.21
Forfeited, weighted average exercise price (dollars per share)	$ 40.08
Exercised, weighted average exercise price (dollars per share)	$ 26.35
Ending balance, weighted average exercise price (dollars per share)	$ 37.96
Vested and expected to vest, weighted average exercise price (dollars per share)	$ 37.99
Exercisable, weighted average exercise price (dollars per share)	$ 38.09
Weighted Average Remaining Contractual Term Years [Abstract]
Outstanding balance, weighted average remaining contractual term (years)	6 years 1 month 10 days
Vested and expected to vest, weighted average remaining contractual term (years)	6 years 0 months 15 days
Exercisable, weighted average remaining contractual term (years)	4 years 6 months 26 days
Aggregate Intrinsic Value [Abstract]
Vested and expected to vest, aggregate intrinsic value	$ 146
Exercisable, aggregate intrinsic value	88
Southern California Edison
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance (number of options)	10,526,540
Grants (number of options)	2,072,892
Expired (number of options)	(107,854)
Forfeited (number of options)	(176,938)
Exercised (number of options)	(2,173,557)
Affiliate transfers, net (number of options)	167,378
Ending balance (number of options)	10,308,461
Vested and expected to vest (number of options)	9,952,333
Exercisable (number of options)	5,683,815
Weighted Average Exercise Price [Roll Forward]
Beginning balance, weighted average exercise price (dollars per share)	$ 34.60
Granted, weighted average exercise price (dollars per share)	$ 43.21
Expired, weighted average exercise price (dollars per share)	$ 49.06
Forfeited, weighted average exercise price (dollars per share)	$ 39.79
Exercised, weighted average exercise price (dollars per share)	$ 26.90
Affiliate transfers, net, weighted average exercise price (dollars per share)	$ 35.42
Ending balance, weighted average exercise price (dollars per share)	$ 37.73
Vested and expected to vest, weighted average exercise price (dollars per share)	$ 37.74
Exercisable, weighted average exercise price (dollars per share)	$ 37.12
Weighted Average Remaining Contractual Term Years [Abstract]
Outstanding balance, weighted average remaining contractual term (years)	6 years 1 month 21 days
Vested and expected to vest, weighted average remaining contractual term (years)	6 years 0 months 29 days
Exercisable, weighted average remaining contractual term (years)	4 years 6 months 4 days
Aggregate Intrinsic Value [Abstract]
Vested and expected to vest, aggregate intrinsic value	81
Exercisable, aggregate intrinsic value	$ 48