Commitments and Contingencies	6 Months Ended
Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Indemnities Edison International and SCE have various financial and performance guarantees and indemnity agreements, which are issued in the normal course of business. Edison International and SCE have provided indemnifications through contracts entered into in the normal course of business. These are primarily indemnifications against adverse litigation outcomes in connection with underwriting agreements, and indemnities for specified environmental liabilities and income taxes with respect to assets sold. Edison International's and SCE's obligations under these agreements may or may not be limited in terms of time and/or amount, and in some instances Edison International and SCE may have recourse against third parties. Edison International and SCE have not recorded a liability related to these indemnities. The overall maximum amount of the obligations under these indemnifications cannot be reasonably estimated. SCE has indemnified the City of Redlands, California in connection with Mountainview's California Energy Commission permit for cleanup or associated actions related to groundwater contaminated by perchlorate due to the disposal of filter cake at the City's solid waste landfill. The obligations under this agreement are not limited to a specific time period or subject to a maximum liability. SCE has not recorded a liability related to this indemnity. Contingencies In addition to the matters disclosed in these Notes, Edison International and SCE are involved in other legal, tax and regulatory proceedings before various courts and governmental agencies regarding matters arising in the ordinary course of business. Edison International and SCE believe the outcome of these other proceedings will not, individually or in the aggregate, materially affect its results of operations or liquidity. San Onofre Related Matters Replacement steam generators were installed at San Onofre in 2010 and 2011. On January 31, 2012, a leak suddenly occurred in one of the heat transfer tubes in San Onofre's Unit 3 steam generators. The Unit was safely taken off-line and subsequent inspections revealed excessive tube wear. Unit 2 was off-line for a planned outage when areas of unexpected tube wear were also discovered. On June 6, 2013, SCE decided to permanently retire Units 2 and 3. San Onofre CPUC Proceedings The San Onofre OII Settlement Agreement resolved the CPUC's investigation regarding the Steam Generator Replacement Project at San Onofre and the related outages and subsequent shutdown of San Onofre. In May 2016, and in consideration of the CPUC's December 2015 decision sanctioning SCE for failing to disclose ex parte communications relevant to the San Onofre OII, the Assigned Commissioner and ALJ issued a ruling to reopen the record upon which the CPUC had, in November 2014, approved the San Onofre OII Settlement Agreement among SCE, TURN, ORA, SDG&E, the Coalition of California Utility Employees, and Friends of the Earth. The ruling also established a ban on all ex parte communications in the proceeding. The ruling established a briefing schedule for parties to address whether, in light of the ex parte rules violations, the San Onofre OII Settlement Agreement remains reasonable, consistent with the law and in the public interest, which is the standard the CPUC applies in reviewing settlements submitted for approval. In comments filed with the CPUC in July 2016, SCE asserts that the San Onofre OII Settlement Agreement continues to meet this standard and therefore should not be disturbed. A number of parties, however, have asked the CPUC in their comments to either modify the San Onofre OII Settlement Agreement or vacate its previous approval of the settlement and reinstate the San Onofre OII for further proceedings. SCE is unable to predict the outcome of this matter. The San Onofre OII Settlement Agreement does not affect proceedings related to recoveries from third parties described below, but does describe how shareholders and customers will share any recoveries. Challenges related to San Onofre CPUC Proceedings A federal lawsuit challenging the CPUC's authority to permit rate recovery of San Onofre costs and an application to the CPUC for rehearing of its decision approving the San Onofre OII Settlement Agreement were filed in November and December 2014, respectively. In April 2015, the federal lawsuit was dismissed with prejudice and the plaintiffs in that case appealed the dismissal to the Ninth Circuit in May 2015. Both the appeal and the application for rehearing remain pending. In April 2015, the Alliance for Nuclear Responsibility ("A4NR") filed a petition to modify the CPUC's decision approving the San Onofre OII Settlement Agreement based on SCE's alleged failures to disclose communications between SCE and CPUC decision-makers pertaining to issues in the San Onofre OII. The petition seeks the reversal of the decision approving the San Onofre OII Settlement Agreement and reopening of the OII proceeding. Subsequently, TURN and ORA filed responses supporting A4NR's petition to reopen the San Onofre OII proceeding. In August 2015, ORA filed its own petition to modify the CPUC's decision approving the San Onofre OII Settlement Agreement seeking to set aside the settlement and reopen the San Onofre OII proceeding. SCE and SDG&E responded to this petition in September 2015. Both petitions remain pending before the CPUC. In July 2015, a purported securities class action lawsuit was filed in federal court against Edison International, its Chief Executive Officer and Chief Financial Officer and was later amended to include SCE's former President as a defendant. The lawsuit alleges that the defendants violated the securities laws by failing to disclose that Edison International had ex parte contacts with CPUC decision-makers regarding the San Onofre OII that were either unreported or more extensive than initially reported. The complaint purports to be filed on behalf of a class of persons who acquired Edison International common stock between March 21, 2014 and June 24, 2015. Subsequently and also in July 2015, a federal shareholder derivative lawsuit was filed against members of the Edison International Board of Directors for breach of fiduciary duty and other claims. The federal derivative lawsuit is based on similar allegations to the federal class action securities lawsuit and seeks monetary damages, including punitive damages, and various corporate governance reforms. An additional federal shareholder derivative lawsuit making essentially the same allegations was filed in August and was subsequently consolidated with the July 2015 federal derivative lawsuit. In October 2015, a shareholder derivative lawsuit was filed in California state court against members of the Edison International Board of Directors for breach of fiduciary duty and other claims, making similar allegations to those in the federal derivative lawsuits discussed above. In November 2015, a purported securities class action lawsuit was filed in federal court against Edison International, its Chief Executive Officer and Treasurer by an Edison International employee, alleging claims under the Employee Retirement Income Security Act ("ERISA"). The complaint purports to be filed on behalf of a class of Edison International employees who were participants in the Edison 401(k) Savings Plan and invested in the Edison International Stock Fund between March 27, 2014 and June 24, 2015. The complaint alleges that defendants breached their fiduciary duties because they knew or should have known that investment in the Edison International Stock Fund was imprudent because the price of Edison International common stock was artificially inflated due to Edison International's alleged failure to disclose certain ex parte communications with CPUC decision-makers related to the San Onofre OII. In July 2016, the federal court granted the defendants' motion to dismiss the lawsuit with an opportunity for the plaintiffs to amend their complaint. Edison International and SCE cannot predict the outcome of these proceedings. MHI Claims SCE is also pursuing claims against Mitsubishi Heavy Industries, Ltd. and a related company ("MHI"), which designed and supplied the replacement steam generators. MHI warranted the replacement steam generators for an initial period of 20 years from acceptance and is contractually obligated to repair or replace defective items with dispatch and to pay specified damages for certain repairs. MHI's stated liability under the purchase agreement is limited to $138 million and excludes consequential damages, defined to include "the cost of replacement power;" however, limitations in the contract are subject to applicable exceptions both in the contract and under law. SCE has advised MHI that it believes one or more of such exceptions apply and that MHI's liability is not limited to $138 million. MHI has advised SCE that it disagrees. In October 2013, SCE sent MHI a formal request for binding arbitration under the auspices of the International Chamber of Commerce in accordance with the purchase contract seeking damages for all losses. In the request for arbitration, SCE alleges contract and tort claims and seeks at least $4 billion in damages on behalf of itself and its customers and in its capacity as Operating Agent for San Onofre. MHI has denied any liability and has asserted counterclaims for $41 million, for which SCE has denied any liability. Each of the other San Onofre owners sued MHI, alleging claims arising from MHI's supplying the faulty steam generators. These litigation claims have been stayed pending the arbitration. The other co-owners (SDG&E and Riverside) have been added as additional claimants in the arbitration. The arbitration is being conducted pursuant to a confidentiality order issued by the arbitration panel. Hearings concluded on April 29, 2016. A decision may be issued by year-end 2016 but could be later. SCE, on behalf of itself and the other San Onofre co-owners, has submitted seven invoices to MHI totaling $149 million for steam generator repair costs incurred through April 30, 2013. MHI paid the first invoice of $45 million, while reserving its right to challenge it and subsequently rejected a portion of the first invoice and has not paid further invoices, claiming further documentation is required, which SCE disputes. SCE recorded its share of the invoice paid (approximately $35 million) as a reduction of repair and inspection costs in 2012. Under the San Onofre OII Settlement Agreement, recoveries from MHI (including amounts paid by MHI under the first invoice), if any, will first be applied to reimburse costs incurred in pursuing such recoveries, including litigation costs. To the extent SCE's share of recoveries from MHI exceed such costs, they will be allocated 50% to customers and 50% to SCE. The first $282 million of SCE's customers' portion of such recoveries from MHI will be distributed to customers via a credit to a sub-account of SCE's Base Revenue Requirement Balancing Account ("BRRBA"), reducing revenue requirements from customers. Amounts in excess of the first $282 million distributable to SCE customers will reduce SCE's regulatory asset represented by the unamortized balance of investment in San Onofre base plant, reducing the revenue requirement needed to amortize such investment. The amortization period, however, will be unaffected. Any additional amounts received after the regulatory asset is recovered will be applied to the BRRBA. The San Onofre OII Settlement Agreement provides the utilities with the discretion to resolve the MHI dispute without CPUC approval, but the utilities are obligated to use their best efforts to inform the CPUC of any settlement or other resolution of these disputes to the extent this is possible without compromising any aspect of the resolution. SCE and SDG&E have also agreed to allow the CPUC to review the documentation of any final resolution of the MHI dispute and the litigation costs incurred in pursuing claims against MHI to ensure they are not exorbitant in relation to the recovery obtained. There is no assurance that there will be any recovery from MHI or, if there is a recovery, that it will equal or exceed the litigation costs incurred to pursue the recovery. Energy Efficiency Incentive Mechanism In September 2015, the CPUC granted TURN and ORA requests for rehearing of prior CPUC decisions related to $74.5 million of incentive awards that SCE received for savings achieved by its 2006 – 2008 energy efficiency programs. In March 2016, ORA and TURN filed a joint proposal requesting that the CPUC recalculate SCE's 2006 – 2008 incentive awards and order SCE to refund $39.9 million to its customers. SCE disputes the assertion that SCE should be at risk to repay previously awarded incentives. SCE cannot predict the outcome of these petitions. Long Beach Service Interruptions In July 2015, SCE's customers who are served via the network portion of SCE's electric system in Long Beach, California experienced service interruptions due to multiple underground vault fires and underground cable failures. No personal injuries have been reported in connection with these events and, subject to applicable deductibles, SCE is generally insured against customer claims arising from these events. SCE instituted an internal investigation and commissioned an external investigation of these events and their causes, which revealed that the main cause of the interruptions was a lack of adequate management oversight of the downtown network system. The investigations also revealed deficiencies in maintaining the knowledge base on the configuration and operation of the system, and a lack of sophisticated controls needed to more efficiently and effectively prevent and respond to the cascading events that occurred. On July 14, 2016, the CPUC initiated an investigation ("Long Beach OII") of these events and their causes based on an investigation by the CPUC's Safety and Enforcement Division ("SED"). The SED investigation, among other things, identified problems with maintenance, inspection, and management of SCE's Long Beach electrical system, and emergency response and communications capabilities. The Long Beach OII will consider whether SCE violated statutes, rules or regulations, maintained adequate, accurate, and complete records, and provided sufficient emergency response and communications to various parties during the power outages. SCE has been directed to show cause at hearings why the CPUC should not find it in violation of the relevant statutes, rules and regulations. The OII does not propose a penalty amount. The CPUC may impose penalties in the amount of $500 to $50,000 per day per violation, but SCE is unable to estimate a possible loss or range of loss associated with any penalties that may be imposed by the CPUC in the Long Beach OII. Environmental Remediation SCE records its environmental remediation liabilities when site assessments and/or remedial actions are probable and a range of reasonably likely cleanup costs can be estimated. SCE reviews its sites and measures the liability quarterly, by assessing a range of reasonably likely costs for each identified site using currently available information, including existing technology, presently enacted laws and regulations, experience gained at similar sites, and the probable level of involvement and financial condition of other potentially responsible parties. These estimates include costs for site investigations, remediation, operation and maintenance, monitoring and site closure. Unless there is a single probable amount, SCE records the lower end of this reasonably likely range of costs (reflected in "Other long-term liabilities") at undiscounted amounts as timing of cash flows is uncertain. At June 30, 2016, SCE's recorded estimated minimum liability to remediate its 19 identified material sites (sites in which the upper end of the range of the costs is at least $1 million) was $130 million, including $79 million related to San Onofre. In addition to these sites, SCE also has 39 immaterial sites for which the total minimum recorded liability was $4 million. Of the $134 million total environmental remediation liability for SCE, $128 million has been recorded as a regulatory asset. SCE expects to recover $46 million through an incentive mechanism that allows SCE to recover 90% of its environmental remediation costs at certain sites (SCE may request to include additional sites) and $82 million through a mechanism that allows SCE to recover 100% of the costs incurred at certain sites through customer rates. SCE's identified sites include several sites for which there is a lack of currently available information, including the nature and magnitude of contamination, and the extent, if any, that SCE may be held responsible for contributing to any costs incurred for remediating these sites. Thus, no reasonable estimate of cleanup costs can be made for these sites. The ultimate costs to clean up SCE's identified sites may vary from its recorded liability due to numerous uncertainties inherent in the estimation process, such as: the extent and nature of contamination; the scarcity of reliable data for identified sites; the varying costs of alternative cleanup methods; developments resulting from investigatory studies; the possibility of identifying additional sites; and the time periods over which site remediation is expected to occur. SCE believes that, due to these uncertainties, it is reasonably possible that cleanup costs at the identified material sites and immaterial sites could exceed its recorded liability by up to $165 million and $7 million, respectively. The upper limit of this range of costs was estimated using assumptions least favorable to SCE among a range of reasonably possible outcomes. SCE expects to clean up and mitigate its identified sites over a period of up to 30 years. Remediation costs for each of the next four years are expected to range from $7 million to $23 million. Costs incurred for the six months ended June 30, 2016 and 2015 were $1 million and $3 million, respectively. Based upon the CPUC's regulatory treatment of environmental remediation costs incurred at SCE, SCE believes that costs ultimately recorded will not materially affect its results of operations, financial position or cash flows. There can be no assurance, however, that future developments, including additional information about existing sites or the identification of new sites, will not require material revisions to estimates. Nuclear Insurance SCE is a member of NEIL, a mutual insurance company owned by entities with nuclear facilities. NEIL provides insurance for nuclear property damage, including damages caused by acts of terrorism up to specified limits, and for accidental outages for active facilities. The amount of nuclear property damage insurance purchased for San Onofre and Palo Verde exceeds the minimum federal requirement of $1.06 billion. If NEIL losses at any nuclear facility covered by the arrangement were to exceed the accumulated funds for these insurance programs, SCE could be assessed retrospective premium adjustments of up to approximately $52 million per year. Federal law limits public offsite liability claims for bodily injury and property damage from a nuclear incident to the amount of available financial protection, which is currently approximately $13.4 billion. Based on its ownership interests, SCE could be required to pay a maximum of approximately $255 million per nuclear incident. However, it would have to pay no more than approximately $38 million per incident in any one year. For more information on nuclear insurance coverage, see Note 11 in the 2015 Form 10-K. Wildfire Insurance Severe wildfires in California have given rise to large damage claims against California utilities for fire-related losses alleged to be the result of the failure of electric and other utility equipment. Invoking a California Court of Appeal decision, plaintiffs pursuing these claims have relied on the doctrine of inverse condemnation, which can impose strict liability (including liability for a claimant's attorneys' fees) for property damage. Prolonged drought conditions in California have also increased the duration of the wildfire season and the risk of severe wildfire events. SCE has approximately $910 million of third party insurance coverage for wildfire liabilities for the period from July 2016 to May 2017. SCE's program includes approximately $90 million in self-insurance at various levels within the $910 million of third party insurance coverage, which combined, equals approximately $1 billion. In addition, SCE has a self-insured retention of $10 million per wildfire occurrence. SCE may experience coverage reductions and/or increased insurance costs in future years. No assurance can be given that future losses will not exceed the limits of SCE's insurance coverage. Spent Nuclear Fuel Under federal law, the Department of Energy ("DOE") is responsible for the selection and construction of a facility for the permanent disposal of spent nuclear fuel and high-level radioactive waste. The DOE has not met its contractual obligation to accept spent nuclear fuel. Extended delays by the DOE have led to the construction of costly alternatives and associated siting and environmental issues. Currently, both San Onofre and Palo Verde have interim storage for spent nuclear fuel on site sufficient for their current license period. In June 2010, the United States Court of Federal Claims issued a decision granting SCE and the San Onofre co-owners damages of approximately $142 million (SCE share $112 million) to recover costs incurred through December 31, 2005 for the DOE's failure to meet its obligation to begin accepting spent nuclear fuel from San Onofre. SCE received payment from the federal government in the amount of the damage award. In April 2016, SCE, as operating agent, settled a lawsuit on behalf of the San Onofre owners against the DOE for $162 million, including reimbursement for legal costs (SCE share $124 million) to compensate for damages caused by the DOE's failure to meet its obligation to begin accepting spent nuclear fuel for the period from January 1, 2006 to December 31, 2013. The settlement also provides for a claim submission/audit process for expenses incurred from 2014 – 2016, where SCE will submit a claim for damages caused by the DOE failure to accept spent nuclear fuel each year, followed by a government audit and payment of the claim. This process will make additional legal action to recover damages incurred in 2014 – 2016 unnecessary. All damages recovered by SCE are subject to CPUC review as to how these amounts would be distributed among customers, shareholders, or to offset fuel decommissioning or storage costs.

Commitments and Contingencies

Indemnities

Edison International and SCE have various financial and performance guarantees and indemnity agreements, which are issued in the normal course of business.

Edison International and SCE have provided indemnifications through contracts entered into in the normal course of business. These are primarily indemnifications against adverse litigation outcomes in connection with underwriting agreements, and indemnities for specified environmental liabilities and income taxes with respect to assets sold. Edison International's and SCE's obligations under these agreements may or may not be limited in terms of time and/or amount, and in some instances Edison International and SCE may have recourse against third parties. Edison International and SCE have not recorded a liability related to these indemnities. The overall maximum amount of the obligations under these indemnifications cannot be reasonably estimated.

SCE has indemnified the City of Redlands, California in connection with Mountainview's California Energy Commission permit for cleanup or associated actions related to groundwater contaminated by perchlorate due to the disposal of filter cake at the City's solid waste landfill. The obligations under this agreement are not limited to a specific time period or subject to a maximum liability. SCE has not recorded a liability related to this indemnity.

Contingencies

In addition to the matters disclosed in these Notes, Edison International and SCE are involved in other legal, tax and regulatory proceedings before various courts and governmental agencies regarding matters arising in the ordinary course of business. Edison International and SCE believe the outcome of these other proceedings will not, individually or in the aggregate, materially affect its results of operations or liquidity.

San Onofre Related Matters

Replacement steam generators were installed at San Onofre in 2010 and 2011. On January 31, 2012, a leak suddenly occurred in one of the heat transfer tubes in San Onofre's Unit 3 steam generators. The Unit was safely taken off-line and subsequent inspections revealed excessive tube wear. Unit 2 was off-line for a planned outage when areas of unexpected tube wear were also discovered. On June 6, 2013, SCE decided to permanently retire Units 2 and 3.

San Onofre CPUC Proceedings

The San Onofre OII Settlement Agreement resolved the CPUC's investigation regarding the Steam Generator Replacement Project at San Onofre and the related outages and subsequent shutdown of San Onofre. In May 2016, and in consideration of the CPUC's December 2015 decision sanctioning SCE for failing to disclose ex parte communications relevant to the San Onofre OII, the Assigned Commissioner and ALJ issued a ruling to reopen the record upon which the CPUC had, in November 2014, approved the San Onofre OII Settlement Agreement among SCE, TURN, ORA, SDG&E, the Coalition of California Utility Employees, and Friends of the Earth. The ruling also established a ban on all ex parte communications in the proceeding. The ruling established a briefing schedule for parties to address whether, in light of the ex parte rules violations, the San Onofre OII Settlement Agreement remains reasonable, consistent with the law and in the public interest, which is the standard the CPUC applies in reviewing settlements submitted for approval. In comments filed with the CPUC in July 2016, SCE asserts that the San Onofre OII Settlement Agreement continues to meet this standard and therefore should not be disturbed. A number of parties, however, have asked the CPUC in their comments to either modify the San Onofre OII Settlement Agreement or vacate its previous approval of the settlement and reinstate the San Onofre OII for further proceedings. SCE is unable to predict the outcome of this matter. The San Onofre OII Settlement Agreement does not affect proceedings related to recoveries from third parties described below, but does describe how shareholders and customers will share any recoveries.

Challenges related to San Onofre CPUC Proceedings

A federal lawsuit challenging the CPUC's authority to permit rate recovery of San Onofre costs and an application to the CPUC for rehearing of its decision approving the San Onofre OII Settlement Agreement were filed in November and December 2014, respectively. In April 2015, the federal lawsuit was dismissed with prejudice and the plaintiffs in that case appealed the dismissal to the Ninth Circuit in May 2015. Both the appeal and the application for rehearing remain pending.

In April 2015, the Alliance for Nuclear Responsibility ("A4NR") filed a petition to modify the CPUC's decision approving the San Onofre OII Settlement Agreement based on SCE's alleged failures to disclose communications between SCE and CPUC decision-makers pertaining to issues in the San Onofre OII. The petition seeks the reversal of the decision approving the San Onofre OII Settlement Agreement and reopening of the OII proceeding. Subsequently, TURN and ORA filed responses supporting A4NR's petition to reopen the San Onofre OII proceeding. In August 2015, ORA filed its own petition to modify the CPUC's decision approving the San Onofre OII Settlement Agreement seeking to set aside the settlement and reopen the San Onofre OII proceeding. SCE and SDG&E responded to this petition in September 2015. Both petitions remain pending before the CPUC.

In July 2015, a purported securities class action lawsuit was filed in federal court against Edison International, its Chief Executive Officer and Chief Financial Officer and was later amended to include SCE's former President as a defendant. The lawsuit alleges that the defendants violated the securities laws by failing to disclose that Edison International had ex parte contacts with CPUC decision-makers regarding the San Onofre OII that were either unreported or more extensive than initially reported. The complaint purports to be filed on behalf of a class of persons who acquired Edison International common stock between March 21, 2014 and June 24, 2015.

Subsequently and also in July 2015, a federal shareholder derivative lawsuit was filed against members of the Edison International Board of Directors for breach of fiduciary duty and other claims. The federal derivative lawsuit is based on similar allegations to the federal class action securities lawsuit and seeks monetary damages, including punitive damages, and various corporate governance reforms. An additional federal shareholder derivative lawsuit making essentially the same allegations was filed in August and was subsequently consolidated with the July 2015 federal derivative lawsuit.

In October 2015, a shareholder derivative lawsuit was filed in California state court against members of the Edison International Board of Directors for breach of fiduciary duty and other claims, making similar allegations to those in the federal derivative lawsuits discussed above.

In November 2015, a purported securities class action lawsuit was filed in federal court against Edison International, its Chief Executive Officer and Treasurer by an Edison International employee, alleging claims under the Employee Retirement Income Security Act ("ERISA"). The complaint purports to be filed on behalf of a class of Edison International employees who were participants in the Edison 401(k) Savings Plan and invested in the Edison International Stock Fund between March 27, 2014 and June 24, 2015. The complaint alleges that defendants breached their fiduciary duties because they knew or should have known that investment in the Edison International Stock Fund was imprudent because the price of Edison International common stock was artificially inflated due to Edison International's alleged failure to disclose certain ex parte communications with CPUC decision-makers related to the San Onofre OII. In July 2016, the federal court granted the defendants' motion to dismiss the lawsuit with an opportunity for the plaintiffs to amend their complaint.

Edison International and SCE cannot predict the outcome of these proceedings.

MHI Claims

SCE is also pursuing claims against Mitsubishi Heavy Industries, Ltd. and a related company ("MHI"), which designed and supplied the replacement steam generators. MHI warranted the replacement steam generators for an initial period of 20 years from acceptance and is contractually obligated to repair or replace defective items with dispatch and to pay specified damages for certain repairs. MHI's stated liability under the purchase agreement is limited to $138 million and excludes consequential damages, defined to include "the cost of replacement power;" however, limitations in the contract are subject to applicable exceptions both in the contract and under law. SCE has advised MHI that it believes one or more of such exceptions apply and that MHI's liability is not limited to $138 million. MHI has advised SCE that it disagrees. In October 2013, SCE sent MHI a formal request for binding arbitration under the auspices of the International Chamber of Commerce in accordance with the purchase contract seeking damages for all losses. In the request for arbitration, SCE alleges contract and tort claims and seeks at least $4 billion in damages on behalf of itself and its customers and in its capacity as Operating Agent for San Onofre. MHI has denied any liability and has asserted counterclaims for $41 million, for which SCE has denied any liability. Each of the other San Onofre owners sued MHI, alleging claims arising from MHI's supplying the faulty steam generators. These litigation claims have been stayed pending the arbitration. The other co-owners (SDG&E and Riverside) have been added as additional claimants in the arbitration. The arbitration is being conducted pursuant to a confidentiality order issued by the arbitration panel. Hearings concluded on April 29, 2016. A decision may be issued by year-end 2016 but could be later.

SCE, on behalf of itself and the other San Onofre co-owners, has submitted seven invoices to MHI totaling $149 million for steam generator repair costs incurred through April 30, 2013. MHI paid the first invoice of $45 million, while reserving its right to challenge it and subsequently rejected a portion of the first invoice and has not paid further invoices, claiming further documentation is required, which SCE disputes. SCE recorded its share of the invoice paid (approximately $35 million) as a reduction of repair and inspection costs in 2012.

Under the San Onofre OII Settlement Agreement, recoveries from MHI (including amounts paid by MHI under the first invoice), if any, will first be applied to reimburse costs incurred in pursuing such recoveries, including litigation costs. To the extent SCE's share of recoveries from MHI exceed such costs, they will be allocated 50% to customers and 50% to SCE.

The first $282 million of SCE's customers' portion of such recoveries from MHI will be distributed to customers via a credit to a sub-account of SCE's Base Revenue Requirement Balancing Account ("BRRBA"), reducing revenue requirements from customers. Amounts in excess of the first $282 million distributable to SCE customers will reduce SCE's regulatory asset represented by the unamortized balance of investment in San Onofre base plant, reducing the revenue requirement needed to amortize such investment. The amortization period, however, will be unaffected. Any additional amounts received after the regulatory asset is recovered will be applied to the BRRBA.

The San Onofre OII Settlement Agreement provides the utilities with the discretion to resolve the MHI dispute without CPUC approval, but the utilities are obligated to use their best efforts to inform the CPUC of any settlement or other resolution of these disputes to the extent this is possible without compromising any aspect of the resolution. SCE and SDG&E have also agreed to allow the CPUC to review the documentation of any final resolution of the MHI dispute and the litigation costs incurred in pursuing claims against MHI to ensure they are not exorbitant in relation to the recovery obtained. There is no assurance that there will be any recovery from MHI or, if there is a recovery, that it will equal or exceed the litigation costs incurred to pursue the recovery.

Energy Efficiency Incentive Mechanism

In September 2015, the CPUC granted TURN and ORA requests for rehearing of prior CPUC decisions related to $74.5 million of incentive awards that SCE received for savings achieved by its 2006 – 2008 energy efficiency programs. In March 2016, ORA and TURN filed a joint proposal requesting that the CPUC recalculate SCE's 2006 – 2008 incentive awards and order SCE to refund $39.9 million to its customers. SCE disputes the assertion that SCE should be at risk to repay previously awarded incentives. SCE cannot predict the outcome of these petitions.

Long Beach Service Interruptions

In July 2015, SCE's customers who are served via the network portion of SCE's electric system in Long Beach, California experienced service interruptions due to multiple underground vault fires and underground cable failures. No personal injuries have been reported in connection with these events and, subject to applicable deductibles, SCE is generally insured against customer claims arising from these events. SCE instituted an internal investigation and commissioned an external investigation of these events and their causes, which revealed that the main cause of the interruptions was a lack of adequate management oversight of the downtown network system. The investigations also revealed deficiencies in maintaining the knowledge base on the configuration and operation of the system, and a lack of sophisticated controls needed to more efficiently and effectively prevent and respond to the cascading events that occurred. On July 14, 2016, the CPUC initiated an investigation ("Long Beach OII") of these events and their causes based on an investigation by the CPUC's Safety and Enforcement Division ("SED"). The SED investigation, among other things, identified problems with maintenance, inspection, and management of SCE's Long Beach electrical system, and emergency response and communications capabilities. The Long Beach OII will consider whether SCE violated statutes, rules or regulations, maintained adequate, accurate, and complete records, and provided sufficient emergency response and communications to various parties during the power outages. SCE has been directed to show cause at hearings why the CPUC should not find it in violation of the relevant statutes, rules and regulations. The OII does not propose a penalty amount. The CPUC may impose penalties in the amount of $500 to $50,000 per day per violation, but SCE is unable to estimate a possible loss or range of loss associated with any penalties that may be imposed by the CPUC in the Long Beach OII.

Environmental Remediation

SCE records its environmental remediation liabilities when site assessments and/or remedial actions are probable and a range of reasonably likely cleanup costs can be estimated. SCE reviews its sites and measures the liability quarterly, by assessing a range of reasonably likely costs for each identified site using currently available information, including existing technology, presently enacted laws and regulations, experience gained at similar sites, and the probable level of involvement and financial condition of other potentially responsible parties. These estimates include costs for site investigations, remediation, operation and maintenance, monitoring and site closure. Unless there is a single probable amount, SCE records the lower end of this reasonably likely range of costs (reflected in "Other long-term liabilities") at undiscounted amounts as timing of cash flows is uncertain.

At June 30, 2016, SCE's recorded estimated minimum liability to remediate its 19 identified material sites (sites in which the upper end of the range of the costs is at least $1 million) was $130 million, including $79 million related to San Onofre. In addition to these sites, SCE also has 39 immaterial sites for which the total minimum recorded liability was $4 million. Of the $134 million total environmental remediation liability for SCE, $128 million has been recorded as a regulatory asset. SCE expects to recover $46 million through an incentive mechanism that allows SCE to recover 90% of its environmental remediation costs at certain sites (SCE may request to include additional sites) and $82 million through a mechanism that allows SCE to recover 100% of the costs incurred at certain sites through customer rates. SCE's identified sites include several sites for which there is a lack of currently available information, including the nature and magnitude of contamination, and the extent, if any, that SCE may be held responsible for contributing to any costs incurred for remediating these sites. Thus, no reasonable estimate of cleanup costs can be made for these sites.

The ultimate costs to clean up SCE's identified sites may vary from its recorded liability due to numerous uncertainties inherent in the estimation process, such as: the extent and nature of contamination; the scarcity of reliable data for identified sites; the varying costs of alternative cleanup methods; developments resulting from investigatory studies; the possibility of identifying additional sites; and the time periods over which site remediation is expected to occur. SCE believes that, due to these uncertainties, it is reasonably possible that cleanup costs at the identified material sites and immaterial sites could exceed its recorded liability by up to $165 million and $7 million, respectively. The upper limit of this range of costs was estimated using assumptions least favorable to SCE among a range of reasonably possible outcomes.

SCE expects to clean up and mitigate its identified sites over a period of up to 30 years. Remediation costs for each of the next four years are expected to range from $7 million to $23 million. Costs incurred for the six months ended June 30, 2016 and 2015 were $1 million and $3 million, respectively.

Based upon the CPUC's regulatory treatment of environmental remediation costs incurred at SCE, SCE believes that costs ultimately recorded will not materially affect its results of operations, financial position or cash flows. There can be no assurance, however, that future developments, including additional information about existing sites or the identification of new sites, will not require material revisions to estimates.

Nuclear Insurance

SCE is a member of NEIL, a mutual insurance company owned by entities with nuclear facilities. NEIL provides insurance for nuclear property damage, including damages caused by acts of terrorism up to specified limits, and for accidental outages for active facilities. The amount of nuclear property damage insurance purchased for San Onofre and Palo Verde exceeds the minimum federal requirement of $1.06 billion. If NEIL losses at any nuclear facility covered by the arrangement were to exceed the accumulated funds for these insurance programs, SCE could be assessed retrospective premium adjustments of up to approximately $52 million per year.

Federal law limits public offsite liability claims for bodily injury and property damage from a nuclear incident to the amount of available financial protection, which is currently approximately $13.4 billion. Based on its ownership interests, SCE could be required to pay a maximum of approximately $255 million per nuclear incident. However, it would have to pay no more than approximately $38 million per incident in any one year.

For more information on nuclear insurance coverage, see Note 11 in the 2015 Form 10-K.

Wildfire Insurance

Severe wildfires in California have given rise to large damage claims against California utilities for fire-related losses alleged to be the result of the failure of electric and other utility equipment. Invoking a California Court of Appeal decision, plaintiffs pursuing these claims have relied on the doctrine of inverse condemnation, which can impose strict liability (including liability for a claimant's attorneys' fees) for property damage. Prolonged drought conditions in California have also increased the duration of the wildfire season and the risk of severe wildfire events. SCE has approximately $910 million of third party insurance coverage for wildfire liabilities for the period from July 2016 to May 2017. SCE's program includes approximately $90 million in self-insurance at various levels within the $910 million of third party insurance coverage, which combined, equals approximately $1 billion. In addition, SCE has a self-insured retention of $10 million per wildfire occurrence. SCE may experience coverage reductions and/or increased insurance costs in future years. No assurance can be given that future losses will not exceed the limits of SCE's insurance coverage.

Spent Nuclear Fuel

Under federal law, the Department of Energy ("DOE") is responsible for the selection and construction of a facility for the permanent disposal of spent nuclear fuel and high-level radioactive waste. The DOE has not met its contractual obligation to accept spent nuclear fuel. Extended delays by the DOE have led to the construction of costly alternatives and associated siting and environmental issues. Currently, both San Onofre and Palo Verde have interim storage for spent nuclear fuel on site sufficient for their current license period.

In June 2010, the United States Court of Federal Claims issued a decision granting SCE and the San Onofre co-owners damages of approximately $142 million (SCE share $112 million) to recover costs incurred through December 31, 2005 for the DOE's failure to meet its obligation to begin accepting spent nuclear fuel from San Onofre. SCE received payment from the federal government in the amount of the damage award. In April 2016, SCE, as operating agent, settled a lawsuit on behalf of the San Onofre owners against the DOE for $162 million, including reimbursement for legal costs (SCE share $124 million) to compensate for damages caused by the DOE's failure to meet its obligation to begin accepting spent nuclear fuel for the period from January 1, 2006 to December 31, 2013. The settlement also provides for a claim submission/audit process for expenses incurred from 2014 – 2016, where SCE will submit a claim for damages caused by the DOE failure to accept spent nuclear fuel each year, followed by a government audit and payment of the claim. This process will make additional legal action to recover damages incurred in 2014 – 2016 unnecessary. All damages recovered by SCE are subject to CPUC review as to how these amounts would be distributed among customers, shareholders, or to offset fuel decommissioning or storage costs.