Compensation and Benefit Plans (Other Postretirement Plan Assets - Fair Value Levels) (Details) (Postretirement Benefits Other Than Pensions, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	2,086		2,065		$ 1,800
Private bond
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation percentage of US equity securities	4.00%		6.00%
Undervalued Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation percentage of US equity securities	17.00%		7.00%
Collateralized mortgage obligations and other asset backed securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Receivables and payables, net	31		29
Municipal Notes
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	111		76
Russell 200 and Russell 1000 indexes | Corporate stocks
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Performance percentage benchmark	47.00%		50.00%
Russell 1000 index | Common or collective equity funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Performance percentage benchmark	38.00%		60.00%
Morgan Stanley Capital International Europe Australasia And Far East Index | Equity index fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Performance percentage benchmark	41.00%		23.00%
MSCI All Country World Index | Corporate stocks
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Performance percentage benchmark	53.00%		50.00%
Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	105		164		166
Level 3 | Asset backed securities including distressed mortgages
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual plan asset allocations	50.00%		78.00%
Southern California Edison
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	2,159		2,063
Receivables and payables, net	(73)		2
Fair Value of Plan Assets	2,086		2,065		1,800
Southern California Edison | Common/collective funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	431	[1]	863	[1]
Southern California Edison | Corporate stocks
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	250	[2]	451	[2]
Southern California Edison | Corporate notes and bonds securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	883	[3]	250	[3]
Southern California Edison | Partnerships/joint ventures
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	124	[4]	184	[4]
Southern California Edison | U.S. government and agency securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	243	[5]	154	[5]
Southern California Edison | Registered investment companies
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	69	[6]	57	[6]
Southern California Edison | Interest bearing cash
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	29		19
Southern California Edison | Other
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	130	[7]	85	[7]
Southern California Edison | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	555		647
Southern California Edison | Level 1 | Common/collective funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	0	[1]	0	[1]
Southern California Edison | Level 1 | Corporate stocks
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	250	[2]	451	[2]
Southern California Edison | Level 1 | Corporate notes and bonds securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	0	[3]	0	[3]
Southern California Edison | Level 1 | Partnerships/joint ventures
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	0	[4]	0	[4]
Southern California Edison | Level 1 | U.S. government and agency securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	207	[5]	118	[5]
Southern California Edison | Level 1 | Registered investment companies
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	64	[6]	52	[6]
Southern California Edison | Level 1 | Interest bearing cash
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	29		19
Southern California Edison | Level 1 | Other
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	5	[7]	7	[7]
Southern California Edison | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	1,499		1,252
Southern California Edison | Level 2 | Common/collective funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	431	[1]	863	[1]
Southern California Edison | Level 2 | Corporate stocks
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	0	[2]	0	[2]
Southern California Edison | Level 2 | Corporate notes and bonds securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	883	[3]	250	[3]
Southern California Edison | Level 2 | Partnerships/joint ventures
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	19	[4]	20	[4]
Southern California Edison | Level 2 | U.S. government and agency securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	36	[5]	36	[5]
Southern California Edison | Level 2 | Registered investment companies
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	5	[6]	5	[6]
Southern California Edison | Level 2 | Interest bearing cash
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	0		0
Southern California Edison | Level 2 | Other
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	125	[7]	78	[7]
Southern California Edison | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	105		164
Southern California Edison | Level 3 | Common/collective funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	0	[1]	0	[1]
Southern California Edison | Level 3 | Corporate stocks
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	0	[2]	0	[2]
Southern California Edison | Level 3 | Corporate notes and bonds securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	0	[3]	0	[3]
Southern California Edison | Level 3 | Partnerships/joint ventures
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	105	[4]	164	[4]
Southern California Edison | Level 3 | U.S. government and agency securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	0	[5]	0	[5]
Southern California Edison | Level 3 | Registered investment companies
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	0	[6]	0	[6]
Southern California Edison | Level 3 | Interest bearing cash
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	0		0
Southern California Edison | Level 3 | Other
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets, Gross	0	[7]	0	[7]

[1] At December 31, 2014 and 2013, respectively, 38% and 60% of the common/collective assets are invested in a large cap index fund which seeks to track performance of the Russell 1000 index. 41% and 23% of the assets in this category are in index funds which seek to track performance in the MSCI Europe, Australasia and Far East (EAFE) Index. 4% and 6% of this category are invested in a privately managed bond fund and 17% and 7% in a fund which invests in equity securities the fund manager believes are undervalue

[2] Corporate stock performance is primarily benchmarked against the Russell Indexes (47% and 50%) and the MSCI All Country World (ACWI) index (53% and 50%) for 2014 and 2013, respectivel

[3] Corporate notes and bonds are diversified and include approximately $31 million and $29 million for commercial collateralized mortgage obligations and other asset backed securities at December 31, 2014 and 2013, respectively.

[4] At December 31, 2014 and 2013, respectively, 50% and 78% of the Level 3 partnerships category is invested in (1) asset backed securities including distressed mortgages, (2) distressed companies and (3) commercial and residential loans and debt and equity of banks.

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

[6] Level 1 registered investment companies consist of an investment grade corporate bond mutual fund and a money market fund.

[7] Other includes $111 million and $76 million of municipal securities at December 31, 2014 and 2013, respectively.