Compensation and Benefit Plans (Pension Plan Assets - Fair Value Levels) (Details) (Pension Plans, USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	$ 3,558		$ 3,580
Receivables and payables, net	(81)		(38)
Fair Value of Plan Assets	3,477		3,542		3,153
Level 1
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	978		1,108
Level 2
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	2,190		2,058
Level 3
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	390		414
Fair Value of Plan Assets	390		414		448
U.S. government and agency securities
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	666	[1]	592	[1]
U.S. government and agency securities | Level 1
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	195	[1]	242	[1]
U.S. government and agency securities | Level 2
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	471	[1]	350	[1]
U.S. government and agency securities | Level 3
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0	[1]	0	[1]
Corporate stocks
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	653	[2]	743	[2]
Corporate stocks | Level 1
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	653	[2]	743	[2]
Corporate stocks | Level 2
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0	[2]	0	[2]
Corporate stocks | Level 3
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0	[2]	0	[2]
Corporate bonds
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	553	[3]	508	[3]
Corporate bonds | Level 1
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0	[3]	0	[3]
Corporate bonds | Level 2
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	553	[3]	508	[3]
Corporate bonds | Level 3
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0	[3]	0	[3]
Common/collective funds
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	546		635	[4]
Common/collective funds | Level 1
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0		0	[4]
Common/collective funds | Level 2
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	546		635	[4]
Common/collective funds | Level 3
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0		0	[4]
Partnerships/joint ventures
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	538	[5]	580	[5]
Partnerships/joint ventures | Level 1
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0	[5]	0	[5]
Partnerships/joint ventures | Level 2
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	148	[5]	166	[5]
Partnerships/joint ventures | Level 3
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	390	[5]	414	[5]
Other investment entities
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	282	[6]	271	[6]
Other investment entities | Level 1
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0	[6]	0	[6]
Other investment entities | Level 2
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	282	[6]	271	[6]
Other investment entities | Level 3
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0	[6]	0	[6]
Registered investment companies
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	193	[7]	126	[7]
Registered investment companies | Level 1
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	112	[7]	98	[7]
Registered investment companies | Level 2
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	81	[7]	28	[7]
Registered investment companies | Level 3
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0	[7]	0	[7]
Interest-bearing cash
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	12		24
Interest-bearing cash | Level 1
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	12		24
Interest-bearing cash | Level 2
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0		0
Interest-bearing cash | Level 3
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0		0
Other
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	115		101
Other | Level 1
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	6		1
Other | Level 2
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	109		100
Other | Level 3
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	0		0
Asset backed securities including distressed mortgages | Level 3
Pension and Other Postretirement Benefits
Actual plan asset allocations	64.00%		56.00%
Non-index fund
Pension and Other Postretirement Benefits
Performance percentage benchmark	23.00%		25.00%
Global asset allocation fund
Pension and Other Postretirement Benefits
Actual plan asset allocations	6.00%		6.00%
Collateralized mortgage obligations and other asset backed securities
Pension and Other Postretirement Benefits
Fair Value of Plan Assets, Gross	78		65
Defined Benefit Plan, Fair Value of Plan Assets below Investment Grade	15		7
Russell 200 and Russell 1000 indexes | Corporate stocks
Pension and Other Postretirement Benefits
Performance percentage benchmark	51.00%		60.00%
Russell 200 and Russell 1000 indexes | Undervalued Securities
Pension and Other Postretirement Benefits
Performance percentage benchmark	28.00%		28.00%
Morgan Stanley Capital International | Corporate stocks
Pension and Other Postretirement Benefits
Performance percentage benchmark	49.00%		40.00%
Standard And Poors 500 Index | Equity index fund
Pension and Other Postretirement Benefits
Performance percentage benchmark	27.00%		29.00%
Morgan Stanley Capital International Europe Australasia And Far East Index | Equity index fund
Pension and Other Postretirement Benefits
Performance percentage benchmark	15.00%		11.00%
Southern California Edison
Pension and Other Postretirement Benefits
Fair Value of Plan Assets	3,236		3,320		2,971
Edison International Parent and Other
Pension and Other Postretirement Benefits
Fair Value of Plan Assets	6		7
Edison Mission Energy
Pension and Other Postretirement Benefits
Fair Value of Plan Assets	$ 235		$ 215

[1] Corporate stocks are diversified. For 2013 and 2012, respectively, performance is primarily benchmarked against the Russell Indexes (51% and 60%) and Morgan Stanley Capital International (MSCI) index (49% and 40%).

[2] Level 1 U.S. government and agency securities are U.S. treasury bonds and notes. Level 2 primarily relates to the Federal National Mortgage Association and the Federal Home Loan Mortgage Corporation.

[3] Corporate bonds are diversified. At December 31, 2013 and 2012, respectively, this category includes $78 million and $65 million for collateralized mortgage obligations and other asset backed securities of which $15 million and $7 million are below investment grade.

[4] At December 31, 2013 and 2012, respectively, the common/collective assets were invested in equity index funds that seek to track performance of the Standard and Poor's (S&P 500) Index (27% and 29%), Russell 1000 indexes (28% and 28%) and the MSCI Europe, Australasia and Far East (EAFE) Index (15% and 11%). A non-index U.S. equity fund representing 23% and 25% of this category for 2013 and 2012, respectively, is actively managed. Another fund representing 6% and 6% of this category for 2013 and 2012, respectively, is a global asset allocation fund

[5] Partnerships/joint venture Level 2 investments consist primarily of a partnership which invests in publicly traded fixed income securities, primarily from the banking and finance industry and U.S. government agencies. At December 31, 2013 and 2012, respectively, approximately 64% and 56% of the Level 3 partnerships are invested in (1) asset backed securities, including distressed mortgages and (2) commercial and residential loans and debt and equity of banks. The remaining Level 3 partnerships are invested in small private equity and venture capital funds. Investment strategies for these funds include branded consumer products, early stage technology, California geographic focus, and diversified US and non-US fund-of-funds.

[6] Other investment entities were primarily invested in (1) emerging market equity securities, (2) a hedge fund that invests through liquid instruments in a global diversified portfolio of equity, fixed income, interest rate, foreign currency and commodities markets, and (3) domestic mortgage backed securitie

[7] Level 1 of registered investment companies primarily consisted of a global equity mutual fund which seeks to outperform the MSCI World Total Return Index. Level 2 primarily consisted of a short-term bond fund.