Planned Sale of Interest in Four Corners (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012
Discontinued Operations and Disposal Groups [Abstract]
Sales price	$ 294
Sales price, after adjustment	$ 279

Sale price, after an adjustment, of the sale of ownership interest of a generating plant.

No definition available.

Name:	eix_SaleOfBusinessSalesPriceAfterAdjustment
Namespace Prefix:	eix_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant