Description Of Business and Significant Accounting Policies	6 Months Ended
Jun. 30, 2015
Description Of Business and Significant Accounting Policies [Abstract]
DESCRIPTION OF BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES	1. BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES Description of Business References in this report to “we,” “our,” “us” and “the company” are to Oncor and/or its subsidiary as apparent in the context. See “Glossary” for definition of terms and abbreviations. We are a regulated electricity transmission and distribution company principally engaged in providing delivery services to REPs, including subsidiaries of TCEH, that sell power in the north-central, eastern and western parts of Texas. Revenues from TCEH represented 24% and 25% of our total operating revenues for the six months ended June 30, 2015 and 2014, respectively. We are a direct, majority-owned subsidiary of Oncor Holdings, which is a direct, wholly-owned subsidiary of EFIH, a direct, wholly-owned subsidiary of EFH Corp. EFH Corp. is a subsidiary of Texas Holdings, which is controlled by the Sponsor Group. Oncor Holdings owns 80.03% of our membership interests, Texas Transmission owns 19.75% of our membership interests and certain members of our management team and board of directors indirectly own the remaining membership interests through Investment LLC. We are managed as an integrated business; consequently, there are no separate reportable business segments. Our consolidated financial statements include our wholly-owned, bankruptcy-remote financing subsidiary, Bondco, a variable interest entity. This financing subsidiary was organized for the limited purpose of issuing certain transition bonds in 2003 and 2004. Bondco issued $1.3 billion principal amount of transition bonds to recover generation-related regulatory asset stranded costs and other qualified costs under an order issued by the PUCT in 2002. Various “ring-fencing” measures have been taken to enhance the separateness between the Oncor Ring-Fenced Entities and the Texas Holdings Group and our credit quality. These measures serve to mitigate our and Oncor Holdings’ credit exposure to the Texas Holdings Group and to reduce the risk that our assets and liabilities or those of Oncor Holdings would be substantively consolidated with the assets and liabilities of the Texas Holdings Group in connection with a bankruptcy of one or more of those entities, including the EFH Bankruptcy Proceedings discussed below. Such measures include, among other things: our sale of a 19.75% equity interest to Texas Transmission in November 2008; maintenance of separate books and records for the Oncor Ring-Fenced Entities; our board of directors being comprised of a majority of independent directors; and prohibitions on the Oncor Ring-Fenced Entities providing credit support to, or receiving credit support from, any member of the Texas Holdings Group. The assets and liabilities of the Oncor Ring-Fenced Entities are separate and distinct from those of the Texas Holdings Group, including TXU Energy and Luminant, and none of the assets of the Oncor Ring-Fenced Entities are available to satisfy the debt or contractual obligations of any member of the Texas Holdings Group. We do not bear any liability for debt or contractual obligations of the Texas Holdings Group, and vice versa. Accordingly, our operations are conducted, and our cash flows are managed, independently from the Texas Holdings Group. EFH Corp. Bankruptcy Proceedings On the EFH Petition Date, EFH Corp. and the substantial majority of its direct and indirect subsidiaries that are members of the Texas Holdings Group, including EFIH, EFCH and TCEH, commenced proceedings under Chapter 11 of the US Bankruptcy Code. The Oncor Ring-Fenced Entities are not parties to the EFH Bankruptcy Proceedings. We believe the “ring-fencing” measures discussed above mitigate our potential exposure to the EFH Bankruptcy Proceedings. See Note 2 for a discussion of the potential impacts of the EFH Bankruptcy Proceedings on our financial statements. Basis of Presentation Our condensed consolidated financial statements have been prepared in accordance with US GAAP and on the same basis as the audited financial statements in our 2014 Form 10-K. Adjustments (consisting of normal recurring accruals) necessary for a fair presentation of the results of operations and financial position have been included therein. All intercompany items and transactions have been eliminated in consolidation. Certain information and footnote disclosures normally included in annual consolidated financial statements prepared in accordance with US GAAP have been omitted pursuant to the rules and regulations of the SEC. Because the condensed consolidated interim financial statements do not include all of the information and footnotes required by US GAAP, they should be read in conjunction with the audited financial statements and related notes in our 2014 Form 10-K. The results of operations for an interim period may not give a true indication of results for a full year due to seasonality. All dollar amounts in the financial statements and tables in the notes are stated in millions of US dollars unless otherwise indicated. Use of Estimates Preparation of our financial statements requires management to make estimates and assumptions about future events that affect the reporting of assets and liabilities at the balance sheet dates and the reported amounts of revenue and expense, including fair value measurements. In the event estimates and/or assumptions prove to be different from actual amounts, adjustments are made in subsequent periods to reflect more current information. Derivative Instruments and Mark-to-Market Accounting We have from time-to-time entered into derivative instruments to hedge interest rate risk. If the instrument meets the definition of a derivative under accounting standards related to derivative instruments and hedging activities, the fair value of each derivative is recognized on the balance sheet as a derivative asset or liability and changes in the fair value are recognized in net income, unless criteria for certain exceptions are met. This recognition is referred to as “mark-to-market” accounting. Reconcilable Tariffs The PUCT has designated certain tariffs (TCRF, EECRF surcharges, AMS surcharges and charges related to transition bonds) as reconcilable, which means the differences between amounts billed under these tariffs and the related incurred costs are deferred as either regulatory assets or regulatory liabilities. Accordingly, at prescribed intervals, future tariffs are adjusted to either repay regulatory liabilities or collect regulatory assets. Contingencies We evaluate and account for contingencies using the best information available. A loss contingency is accrued and disclosed when it is probable that an asset has been impaired or a liability incurred and the amount of the loss can be reasonably estimated. If a range of probable loss is established, the minimum amount in the range is accrued, unless some other amount within the range appears to be a better estimate. If the probable loss cannot be reasonably estimated, no accrual is recorded, but the loss contingency is disclosed to the effect that the probable loss cannot be reasonably estimated. A loss contingency will be disclosed when it is reasonably possible that an asset has been impaired or a liability incurred. If the likelihood that an impairment or incurrence is remote, the contingency is neither accrued nor disclosed. Gain contingencies are recognized upon realization. Changes in Accounting Standards In April 2015, the Financial Accounting Standards Board issued a new accounting standard update, which changes the presentation of debt issuance costs in the balance sheet. The update requires that such costs be presented as a direct reduction to the face value of the related debt rather than as an asset. This will make the presentation of debt issuance costs consistent with debt discounts. The update is effective for interim and annual periods beginning after December 15, 2015. Early application is permitted. When adopted, we anticipate that both other noncurrent assets and long-term debt amounts will decrease by approximately $40 million.

1. BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES

Description of Business

References in this report to “we,” “our,” “us” and “the company” are to Oncor and/or its subsidiary as apparent in the context. See “Glossary” for definition of terms and abbreviations.

We are a regulated electricity transmission and distribution company principally engaged in providing delivery services to REPs, including subsidiaries of TCEH, that sell power in the north-central, eastern and western parts of Texas. Revenues from TCEH represented 24% and 25% of our total operating revenues for the six months ended June 30, 2015 and 2014, respectively. We are a direct, majority-owned subsidiary of Oncor Holdings, which is a direct, wholly-owned subsidiary of EFIH, a direct, wholly-owned subsidiary of EFH Corp. EFH Corp. is a subsidiary of Texas Holdings, which is controlled by the Sponsor Group. Oncor Holdings owns 80.03% of our membership interests, Texas Transmission owns 19.75% of our membership interests and certain members of our management team and board of directors indirectly own the remaining membership interests through Investment LLC. We are managed as an integrated business; consequently, there are no separate reportable business segments.

Our consolidated financial statements include our wholly-owned, bankruptcy-remote financing subsidiary, Bondco, a variable interest entity. This financing subsidiary was organized for the limited purpose of issuing certain transition bonds in 2003 and 2004. Bondco issued $1.3 billion principal amount of transition bonds to recover generation-related regulatory asset stranded costs and other qualified costs under an order issued by the PUCT in 2002.

Various “ring-fencing” measures have been taken to enhance the separateness between the Oncor Ring-Fenced Entities and the Texas Holdings Group and our credit quality. These measures serve to mitigate our and Oncor Holdings’ credit exposure to the Texas Holdings Group and to reduce the risk that our assets and liabilities or those of Oncor Holdings would be substantively consolidated with the assets and liabilities of the Texas Holdings Group in connection with a bankruptcy of one or more of those entities, including the EFH Bankruptcy Proceedings discussed below. Such measures include, among other things: our sale of a 19.75% equity interest to Texas Transmission in November 2008; maintenance of separate books and records for the Oncor Ring-Fenced Entities; our board of directors being comprised of a majority of independent directors; and prohibitions on the Oncor Ring-Fenced Entities providing credit support to, or receiving credit support from, any member of the Texas Holdings Group. The assets and liabilities of the Oncor Ring-Fenced Entities are separate and distinct from those of the Texas Holdings Group, including TXU Energy and Luminant, and none of the assets of the Oncor Ring-Fenced Entities are available to satisfy the debt or contractual obligations of any member of the Texas Holdings Group. We do not bear any liability for debt or contractual obligations of the Texas Holdings Group, and vice versa. Accordingly, our operations are conducted, and our cash flows are managed, independently from the Texas Holdings Group.

EFH Corp. Bankruptcy Proceedings

On the EFH Petition Date, EFH Corp. and the substantial majority of its direct and indirect subsidiaries that are members of the Texas Holdings Group, including EFIH, EFCH and TCEH, commenced proceedings under Chapter 11 of the US Bankruptcy Code. The Oncor Ring-Fenced Entities are not parties to the EFH Bankruptcy Proceedings. We believe the “ring-fencing” measures discussed above mitigate our potential exposure to the EFH Bankruptcy Proceedings. See Note 2 for a discussion of the potential impacts of the EFH Bankruptcy Proceedings on our financial statements.

Basis of Presentation

Our condensed consolidated financial statements have been prepared in accordance with US GAAP and on the same basis as the audited financial statements in our 2014 Form 10-K. Adjustments (consisting of normal recurring accruals) necessary for a fair presentation of the results of operations and financial position have been included therein. All intercompany items and transactions have been eliminated in consolidation. Certain information and footnote disclosures normally included in annual consolidated financial statements prepared in accordance with US GAAP have been omitted pursuant to the rules and regulations of the SEC. Because the condensed consolidated interim financial statements do not include all of the information and footnotes required by US GAAP, they should be read in conjunction with the audited financial statements and related notes in our 2014 Form 10-K. The results of operations for an interim period may not give a true indication of results for a full year due to seasonality. All dollar amounts in the financial statements and tables in the notes are stated in millions of US dollars unless otherwise indicated.

Use of Estimates

Preparation of our financial statements requires management to make estimates and assumptions about future events that affect the reporting of assets and liabilities at the balance sheet dates and the reported amounts of revenue and expense, including fair value measurements. In the event estimates and/or assumptions prove to be different from actual amounts, adjustments are made in subsequent periods to reflect more current information.

Derivative Instruments and Mark-to-Market Accounting

We have from time-to-time entered into derivative instruments to hedge interest rate risk. If the instrument meets the definition of a derivative under accounting standards related to derivative instruments and hedging activities, the fair value of each derivative is recognized on the balance sheet as a derivative asset or liability and changes in the fair value are recognized in net income, unless criteria for certain exceptions are met. This recognition is referred to as “mark-to-market” accounting.

Reconcilable Tariffs

The PUCT has designated certain tariffs (TCRF, EECRF surcharges, AMS surcharges and charges related to transition bonds) as reconcilable, which means the differences between amounts billed under these tariffs and the related incurred costs are deferred as either regulatory assets or regulatory liabilities. Accordingly, at prescribed intervals, future tariffs are adjusted to either repay regulatory liabilities or collect regulatory assets.

Contingencies

We evaluate and account for contingencies using the best information available. A loss contingency is accrued and disclosed when it is probable that an asset has been impaired or a liability incurred and the amount of the loss can be reasonably estimated. If a range of probable loss is established, the minimum amount in the range is accrued, unless some other amount within the range appears to be a better estimate. If the probable loss cannot be reasonably estimated, no accrual is recorded, but the loss contingency is disclosed to the effect that the probable loss cannot be reasonably estimated. A loss contingency will be disclosed when it is reasonably possible that an asset has been impaired or a liability incurred. If the likelihood that an impairment or incurrence is remote, the contingency is neither accrued nor disclosed. Gain contingencies are recognized upon realization.

Changes in Accounting Standards

In April 2015, the Financial Accounting Standards Board issued a new accounting standard update, which changes the presentation of debt issuance costs in the balance sheet. The update requires that such costs be presented as a direct reduction to the face value of the related debt rather than as an asset. This will make the presentation of debt issuance costs consistent with debt discounts. The update is effective for interim and annual periods beginning after December 15, 2015. Early application is permitted. When adopted, we anticipate that both other noncurrent assets and long-term debt amounts will decrease by approximately $40 million.