Summary of Significant Accounting Policies (Earnings Per Share) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Basic earnings per share – continuing operations:
Income from continuing operations, net of tax	$ 299	$ 198
Participating securities dividends	0eix_ParticipatingSecuritiesDividends	0eix_ParticipatingSecuritiesDividends
Income from continuing operations available to common shareholders	299	198
Weighted average common shares outstanding (in shares)	326,000,000	326,000,000
Basic earnings per share – continuing operations (in dollars per share)	$ 0.92	$ 0.61
Diluted earnings per share – continuing operations:
Income from continuing operations, net of tax	299	198
Income impact of assumed conversions	0us-gaap_DilutiveSecurities	0us-gaap_DilutiveSecurities
Income from continuing operations available to common shareholders and assumed conversions	$ 299	$ 198
Weighted average common shares outstanding (in shares)	326,000,000	326,000,000
Incremental shares from assumed conversions (in shares)	3,000,000	3,000,000
Adjusted weighted average shares - diluted (in shares)	329,000,000	329,000,000
Diluted earnings per share – continuing operations (in dollars per share)	$ 0.91	$ 0.61
Stock-Based Compensation Awards
Diluted earnings per share – continuing operations:
Stock-based compensation awards excluded from the computation of diluted earnings per share (in shares)	79,394	2,050,449

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This element includes the amount of dividends declared or paid in the period to participating shareholders or the amount for which the obligation to pay dividends arose in the period. Participating securities are stock based compensation awards payable in common shares, including stock options, performance shares and restricted stock units, which earn dividend equivalents on an equal basis with common shares.

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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Amount of increase (decrease) to net income used for calculating diluted earnings per share (EPS), resulting from the assumed exercise stock options, restrictive stock units (RSUs), convertible preferred stock of an employee stock ownership plan (ESOP), and other dilutive convertible securities.

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Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Net Income or Loss Available to Common Stockholders plus adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions.

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