Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2015
Accounting Policies [Abstract]
Organization and Basis of Presentation	Organization and Basis of Presentation Edison International is the parent holding company of Southern California Edison Company ("SCE"). SCE is an investor-owned public utility primarily engaged in the business of supplying and delivering electricity to an approximately 50,000 square mile area of southern California. Edison International is also the parent company of Edison Energy Group, a company that holds interests in subsidiaries that are engaged in competitive businesses related to the generation, delivery, or use of electricity. Such competitive business activities are currently not material to report as a separate business segment. These combined notes to the consolidated financial statements apply to both Edison International and SCE unless otherwise described. Edison International's consolidated financial statements include the accounts of Edison International, SCE and other wholly owned and controlled subsidiaries. References to Edison International refer to the consolidated group of Edison International and its subsidiaries. References to Edison International Parent and Other refer to Edison International Parent and its nonutility subsidiaries. SCE's consolidated financial statements include the accounts of SCE and its wholly owned and controlled subsidiaries. All intercompany transactions have been eliminated from the consolidated financial statements. Edison International's and SCE's significant accounting policies were described in Note 1 of "Notes to Consolidated Financial Statements" included in the 2014 Form 10-K. This quarterly report should be read in conjunction with the financial statements and notes included in the 2014 Form 10-K. In the opinion of management, all adjustments, consisting of recurring accruals, have been made that are necessary to fairly state the consolidated financial position, results of operations and cash flows in accordance with accounting principles generally accepted in the United States of America for the periods covered by this quarterly report on Form 10-Q. The results of operations for the three- and nine-month periods ended September 30, 2015 are not necessarily indicative of the operating results for the full year. The December 31, 2014 financial statement data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America.
Cash Equivalents	Cash Equivalents Cash equivalents included investments in money market funds. Generally, the carrying value of cash equivalents equals the fair value, as these investments have original maturities of three months or less.
Inventory	Inventory Inventory is primarily composed of materials, supplies and spare parts, and stated at the lower of cost or market, cost being determined by the average cost method.
Earnings Per Share	Earnings Per Share Edison International computes earnings per common share ("EPS") using the two-class method, which is an earnings allocation formula that determines EPS for each class of common stock and participating security. Edison International's participating securities are stock-based compensation awards payable in common shares, including performance shares and restricted stock units, which earn dividend equivalents on an equal basis with common shares once the awards are vested.
New Accounting Guidance	New Accounting Guidance Accounting Guidance Not Yet Adopted On July 22, 2015, the FASB issued an accounting standards update on inventory. Currently, inventory is measured at the lower of cost or market where market could be one of three different measurements. Under the new guidance, inventory (other than for the LIFO or the retail inventory methods) will be subsequently measured at the lower of cost or net realizable value. This standard is effective prospectively on January 1, 2016 and is not expected to have a material impact on Edison International’s and SCE's consolidated financial statements. On May 28, 2014, the FASB issued an accounting standards update on revenue recognition including enhanced disclosures. Under the new standard, revenue is recognized when (or as) a good or service is transferred to the customer and the customer obtains control of the good or service. On July 9, 2015, the FASB approved a one-year deferral, updating the effective date to January 1, 2018. Edison International and SCE are currently evaluating this new guidance and cannot determine the impact of this standard at this time. On April 7, 2015, the FASB issued an accounting standards update that will require debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying amount of the related debt liability, consistent with debt discounts. Currently, these costs are presented as a deferred charge asset. Edison International and SCE will adopt this guidance in the first quarter of 2016. The adoption of this accounting standards update is not expected to have a material impact on Edison International's and SCE's consolidated financial statements. On April 15, 2015, the FASB issued an accounting standard update on fees paid by a customer for software licenses. This new standard provides guidance about whether a cloud computing arrangement includes a software license which may be capitalized in certain circumstances. If a cloud computing arrangement does not include a software license, then the arrangement should be accounted for as a service contract. Edison International and SCE are currently evaluating this guidance, which is effective January 1, 2016, and expects this new standard will not have a material impact on the consolidated financial statements.

Disclosure of accounting policy for major classes of inventories, bases of stating inventories (for example, lower of cost or market), methods by which amounts are added and removed from inventory classes (for example, FIFO, LIFO, or average cost), loss recognition on impairment of inventories, and situations in which inventories are stated above cost. If inventory is carried at cost, this disclosure includes the nature of the cost elements included in inventory.