Income Taxes (Reconciliation of Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Dec. 31, 2013	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Reconciliation of Unrecognized Tax Benefits
Balance at January 1,			$ 576		$ 815		$ 812
Tax positions taken during the current year, Increases			54		65		19
Tax positions taken during a prior year, Increases			66		1		43
Tax positions taken during a prior year, Decreases	[1]		(165)		(143)		(109)
Tax positions taken during a prior year: Increases (decreases) - deconsolidation of EME		$ 50	0	[2]	0	[2]	50	[2]
Tax positions taken during a prior year, Decreases for settlements during the period	[3]		(2)		(162)		0
Balance at December 31,		815	529		576		815
Southern California Edison
Reconciliation of Unrecognized Tax Benefits
Balance at January 1,			441		532		571
Tax positions taken during the current year, Increases			48		57		22
Tax positions taken during a prior year, Increases			23		0		45
Tax positions taken during a prior year, Decreases	[1]		(159)		(93)		(106)
Tax positions taken during a prior year: Increases (decreases) - deconsolidation of EME	[2]		0		0		0
Tax positions taken during a prior year, Decreases for settlements during the period	[3]		0		(55)		0
Balance at December 31,		$ 532	$ 353		$ 441		$ 532

[1] Decreases in prior year tax positions relate primarily to re-measurement of uncertain tax positions in connection with receipt of the IRS Revenue Agent Report in June 2015.

[2] Unrecognized tax benefits of EME have been deconsolidated as a result of the bankruptcy filing by EME, except for tax liabilities for which Edison International and EME are jointly liable under the Internal Revenue Code and applicable state statutes. See Note 15 for further information. During 2013, Edison International increased the amount of unrecognized tax benefits related to the taxable gain on sale of EME’s international assets by approximately $50 million as a result of unfavorable developments during the fourth quarter of 2013.

[3] In the fourth quarter of 2014, Edison International has settled all open tax positions with the IRS for taxable year 2003 through 2006.