Preferred and Preference Stock of Utility (Schedule of Preferred and Preference Stock) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Preferred and Preference Stock of Utility
Preferred and preference stock of utility	$ 2,020	$ 2,022
Southern California Edison
Preferred and Preference Stock of Utility
Preferred and preference stock of utility	$ 2,070	2,070
Southern California Edison | 4.08% Series
Preferred and Preference Stock of Utility
Preferred Stock, dividend rate, (as a percent)	4.08%
Shares Outstanding	650,000
Redemption Price (in dollars per share)	$ 25.5
Preferred stock before issuance costs	$ 16	16
Southern California Edison | 4.24% Series
Preferred and Preference Stock of Utility
Preferred Stock, dividend rate, (as a percent)	4.24%
Shares Outstanding	1,200,000
Redemption Price (in dollars per share)	$ 25.8
Preferred stock before issuance costs	$ 30	30
Southern California Edison | 4.32% Series
Preferred and Preference Stock of Utility
Preferred Stock, dividend rate, (as a percent)	4.32%
Shares Outstanding	1,653,429
Redemption Price (in dollars per share)	$ 28.75
Preferred stock before issuance costs	$ 41	41
Southern California Edison | 4.78% Series
Preferred and Preference Stock of Utility
Preferred Stock, dividend rate, (as a percent)	4.78%
Shares Outstanding	1,296,769
Redemption Price (in dollars per share)	$ 25.8
Preferred stock before issuance costs	$ 33	33
Southern California Edison | Preference stock
Preferred and Preference Stock of Utility
Preferred stock before issuance costs	2,070	2,070
Less issuance costs	(50)	(48)
Preferred and preference stock of utility	$ 2,020	2,022
Southern California Edison | 4.51% Series A (variable and noncumulative)
Preferred and Preference Stock of Utility
Preferred Stock, dividend rate, (as a percent)	4.51%
Shares Outstanding	3,250,000
Redemption Price (in dollars per share)	$ 100
Preferred stock before issuance costs	$ 0	325
Southern California Edison | 6.50% Series D (cumulative)
Preferred and Preference Stock of Utility
Preferred Stock, dividend rate, (as a percent)	6.50%
Shares Outstanding	1,250,000
Redemption Price (in dollars per share)	$ 100
Preferred stock before issuance costs	$ 125	125
Southern California Edison | 6.25% Series E (cumulative)
Preferred and Preference Stock of Utility
Preferred Stock, dividend rate, (as a percent)	6.25%
Shares Outstanding	350,000
Redemption Price (in dollars per share)	$ 1,000
Preferred stock before issuance costs	$ 350	350
Southern California Edison | 5.625% Series F (cumulative)
Preferred and Preference Stock of Utility
Preferred Stock, dividend rate, (as a percent)	5.625%
Shares Outstanding	190,004
Redemption Price (in dollars per share)	$ 2,500
Preferred stock before issuance costs	$ 475	475
Southern California Edison | 5.10% Series G (cumulative)
Preferred and Preference Stock of Utility
Preferred Stock, dividend rate, (as a percent)	5.10%
Shares Outstanding	160,004
Redemption Price (in dollars per share)	$ 2,500.00
Preferred stock before issuance costs	$ 400	400
Southern California Edison | 5.75% Series H (cumulative)
Preferred and Preference Stock of Utility
Preferred Stock, dividend rate, (as a percent)	5.75%
Shares Outstanding	110,004
Redemption Price (in dollars per share)	$ 2,500.00
Preferred stock before issuance costs	$ 275	275
Southern California Edison | 5.375% Series J (cumulative)
Preferred and Preference Stock of Utility
Preferred Stock, dividend rate, (as a percent)	5.375%
Shares Outstanding	130,004
Redemption Price (in dollars per share)	$ 2,500,000,000.00
Preferred stock before issuance costs	$ 325	$ 0
Variable Interest Entity, Not Primary Beneficiary | Southern California Edison Trust III | Southern California Edison | 5.75% Series H (cumulative)
Preferred and Preference Stock of Utility
Preferred Stock, dividend rate, (as a percent)	5.75%	5.75%