Consolidated Statements of Changes in Equity (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013		Jun. 30, 2012
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance			$ 732		$ 1,664
Net Income (loss)	(84)	(104)	(166)		(186)
OCI, net of tax	31	(37)	29		(21)
Payments to EIX for stock purchases related to stock-based compensation			(13)		(12)
Cash contribution from EIX			6	[1]
Excess tax benefits related to stock option exercises			2		1
Other stock transactions, net			1		2
Contributions from noncontrolling interests			94	[2]	242	[2]
Distributions to Noncontrolling Interests			(6)		(7)
Transfers of assets to Capistrano Wind Partners					(21)	[3]
Balance	679	1,662	679		1,662
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance			64		64
Net Income (loss)			0		0
OCI, net of tax			0		0
Payments to EIX for stock purchases related to stock-based compensation			0		0
Cash contribution from EIX			0	[1]
Excess tax benefits related to stock option exercises			0		0
Other stock transactions, net			0		0
Contributions from noncontrolling interests			0	[2]	0	[2]
Distributions to Noncontrolling Interests			0		0
Transfers of assets to Capistrano Wind Partners					0	[3]
Balance	64	64	64		64
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance			1,095		1,327
Net Income (loss)			0		0
OCI, net of tax			0		0
Payments to EIX for stock purchases related to stock-based compensation			0		0
Cash contribution from EIX			6	[1]
Excess tax benefits related to stock option exercises			2		1
Other stock transactions, net			1		2
Contributions from noncontrolling interests			0	[2]	0	[2]
Distributions to Noncontrolling Interests			0		0
Transfers of assets to Capistrano Wind Partners					(21)	[3]
Balance	1,104	1,309	1,104		1,309
Retained Earnings (Deficit)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance			(577)		365
Net Income (loss)			(180)		(193)
OCI, net of tax			0		0
Payments to EIX for stock purchases related to stock-based compensation			(13)		(12)
Cash contribution from EIX			0	[1]
Excess tax benefits related to stock option exercises			0		0
Other stock transactions, net			0		0
Contributions from noncontrolling interests			0	[2]	0	[2]
Distributions to Noncontrolling Interests			0		0
Transfers of assets to Capistrano Wind Partners					0	[3]
Balance	(770)	160	(770)		160
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance			(138)		(94)
Net Income (loss)			0		0
OCI, net of tax			29		(21)
Payments to EIX for stock purchases related to stock-based compensation			0		0
Cash contribution from EIX			0	[1]
Excess tax benefits related to stock option exercises			0		0
Other stock transactions, net			0		0
Contributions from noncontrolling interests			0	[2]	0	[2]
Distributions to Noncontrolling Interests			0		0
Transfers of assets to Capistrano Wind Partners					0	[3]
Balance	(109)	(115)	(109)		(115)
Non-controlling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance			288		2
Net Income (loss)			14		7
OCI, net of tax			0		0
Payments to EIX for stock purchases related to stock-based compensation			0		0
Cash contribution from EIX			0	[1]
Excess tax benefits related to stock option exercises			0		0
Other stock transactions, net			0		0
Contributions from noncontrolling interests			94	[2]	242	[2]
Distributions to Noncontrolling Interests			(6)		(7)
Transfers of assets to Capistrano Wind Partners					0	[3]
Balance	$ 390	$ 244	$ 390		$ 244

[1] During the first quarter of 2013, EME received a cash contribution from EIX related to the tax-allocation agreements. For further information, see Note 7—Income Taxes—EME—Effective Tax Rate.

[2] Funds contributed by third-party investors to Capistrano Wind Partners. For further information, see Note 3—Variable Interest Entities—Projects or Entities that are Consolidated—Capistrano Wind Partners.

[3] Additional paid in capital was reduced by $21 million due to a new tax basis in the assets transferred to Capistrano Wind Partners.