Compensation and Benefit Plans (Stock Option Activity) (Details) - Employee Stock Option $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares
Stock options
Beginning balance (number of options) | shares	13,618,735
Grants (number of options) | shares	2,030,342
Expired (number of options) | shares	0
Forfeited (number of options) | shares	(171,107)
Exercised (number of options) | shares	(2,611,373)
Ending balance (number of options) | shares	12,866,597
Vested and expected to vest (number of options) | shares	12,762,577
Exercisable (number of options) | shares	8,928,807
Exercise Price
Beginning balance, weighted average exercise price (dollars per share) | $ / shares	$ 42.84
Granted, weighted average exercise price (dollars per share) | $ / shares	63.57
Expired, weighted average exercise price (dollars per share) | $ / shares	0.00
Forfeited, weighted average exercise price (dollars per share) | $ / shares	51.87
Exercised, weighted average exercise price (dollars per share) | $ / shares	43.14
Ending balance, weighted average exercise price (dollars per share) | $ / shares	45.93
Vested and expected to vest, weighted average exercise price (dollars per share) | $ / shares	45.81
Exercisable, weighted average exercise price (dollars per share) | $ / shares	$ 40.79
Remaining Contractual Term (Years)
Outstanding at December 31, 2015	5 years 10 months 2 days
Vested and expected to vest at December 31, 2015	5 years 9 months 26 days
Exercisable at December 31, 2015	4 years 8 months 23 days
Aggregate Intrinsic Value (in millions)
Vested and expected to vest at December 31, 2015 | $	$ 180
Exercisable at December 31, 2015 | $	$ 165
Southern California Edison
Stock options
Beginning balance (number of options) | shares	6,002,160
Grants (number of options) | shares	1,099,566
Expired (number of options) | shares	0
Forfeited (number of options) | shares	(109,719)
Exercised (number of options) | shares	(1,085,438)
Transfers, net (number of options) | shares	(66,512)
Ending balance (number of options) | shares	5,840,057
Vested and expected to vest (number of options) | shares	5,771,064
Exercisable (number of options) | shares	3,751,272
Exercise Price
Beginning balance, weighted average exercise price (dollars per share) | $ / shares	$ 43.82
Granted, weighted average exercise price (dollars per share) | $ / shares	63.52
Expired, weighted average exercise price (dollars per share) | $ / shares	0.00
Forfeited, weighted average exercise price (dollars per share) | $ / shares	53.45
Exercised, weighted average exercise price (dollars per share) | $ / shares	41.74
Transfers, net, weighted average exercise price (dollars per share) | $ / shares	40.88
Ending balance, weighted average exercise price (dollars per share) | $ / shares	47.77
Vested and expected to vest, weighted average exercise price (dollars per share) | $ / shares	47.62
Exercisable, weighted average exercise price (dollars per share) | $ / shares	$ 42.17
Remaining Contractual Term (Years)
Outstanding at December 31, 2015	6 years 2 months 12 days
Vested and expected to vest at December 31, 2015	6 years 2 months 1 day
Exercisable at December 31, 2015	4 years 11 months 27 days
Aggregate Intrinsic Value (in millions)
Vested and expected to vest at December 31, 2015 | $	$ 72
Exercisable at December 31, 2015 | $	$ 64