Oncor Electric Delivery 10-Q 28 Apr 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 27, 2017
Entity Registrant Name	ONCOR ELECTRIC DELIVERY CO LLC
Entity Central Index Key	1,193,311
Document Type	10-Q
Document Period End Date	Mar. 31, 2017
Amendment Flag	false
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		0
Oncor's Management and Board of Directors [Member]
Entity Outstanding Membership Interests		0.22%
Oncor Electric Delivery Holdings Company LLC [Member]
Entity Outstanding Membership Interests		80.03%
Texas Transmission Investment LLC [Member]
Entity Outstanding Membership Interests		19.75%

Condensed Statements Of Consoli

Condensed Statements Of Consolidated Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating revenues:
Nonaffiliates	$ 935	$ 723
Affiliates		220
Total operating revenues	935	943
Operating expenses:
Wholesale transmission service	231	219
Operation and maintenance (Note 10)	195	182
Depreciation and amortization	195	211
Provision in lieu of income taxes (Note 10)	42	49
Taxes other than amounts related to income taxes	112	113
Total operating expenses	775	774
Operating income	160	169
Other income and deductions:
Other income and (deductions) - net (Note 11)	(4)	(5)
Nonoperating provision in lieu of income taxes	(2)	(1)
Interest expense and related charges (Note 11)	85	84
Net income	$ 73	$ 81

Condensed Statements Of Consol3

Condensed Statements Of Consolidated Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Condensed Statements Of Consolidated Comprehensive Income [Abstract]
Net income	$ 73	$ 81
Other comprehensive income:
Cash flow hedges – derivative value net loss recognized in net income (net of tax expense of $- and $-) (Note 1)	1
Total other comprehensive income	1
Comprehensive income	$ 74	$ 81

Condensed Statements Of Consol4

Condensed Statements Of Consolidated Comprehensive Income (Parenthetical) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Condensed Statements Of Consolidated Comprehensive Income [Abstract]
Cash flow hedges - derivative value net loss recognized in net income, tax expense

Condensed Statements Of Consol5

Condensed Statements Of Consolidated Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows - operating activities:
Net income	$ 73	$ 81
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	207	223
Provision in lieu of deferred income taxes - net	111	41
Other - net	(1)	(2)
Changes in operating assets and liabilities:
Regulatory accounts related to reconcilable tariffs (Note 4)	(12)	(49)
Other operating assets and liabilities	23	(105)
Cash provided by operating activities	401	189
Cash flows - financing activities:
Net increase in short-term borrowings (Note 5)	91	214
Distributions to members (Note 8)	(86)	(56)
Cash provided by financing activities	5	158
Cash flows - investing activities:
Capital expenditures (Note 10)	(426)	(335)
Other - net	5	(17)
Cash used in investing activities	(421)	(352)
Net change in cash and cash equivalents	(15)	(5)
Cash and cash equivalents - beginning balance	16	25
Cash and cash equivalents - ending balance	$ 1	$ 20

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 1	$ 16
Trade accounts receivable - net (Note 11)	505	545
Amounts receivable from members related to income taxes (Note 10)	6	80
Materials and supplies inventories - at average cost	91	89
Prepayments and other current assets	99	100
Total current assets	702	830
Investments and other property (Note 11)	103	100
Property, plant and equipment - net (Note 11)	14,114	13,829
Goodwill (Note 11)	4,064	4,064
Regulatory assets (Note 4)	1,959	1,974
Other noncurrent assets	6	14
Total assets	20,948	20,811
Current liabilities:
Short-term borrowings (Note 5)	880	789
Long-term debt due currently (Note 6)	324	324
Trade accounts payable (Note 10)	262	231
Amounts payable to members related to income taxes (Note 10)	25	20
Accrued taxes other than amounts related to income	71	182
Accrued interest	69	83
Other current liabilities	137	144
Total current liabilities	1,768	1,773
Long-term debt, less amounts due currently (Note 6)	5,517	5,515
Liability in lieu of deferred income taxes (Note 10)	2,899	2,788
Regulatory liabilities (Note 4)	889	856
Employee benefit obligations and other (Note 10 and 11)	2,176	2,168
Total liabilities	13,249	13,100
Commitments and contingencies (Note 7)
Membership interests (Note 8):
Capital account — number of interests outstanding 2017 and 2016 - 635,000,000	7,809	7,822
Accumulated other comprehensive loss	(110)	(111)
Total membership interests	7,699	7,711
Total liabilities and membership interests	20,948	20,811
Bondco [Member]
Current liabilities:
Long-term debt due currently (Note 6)	$ 324	$ 324

Condensed Consolidated Balance7

Condensed Consolidated Balance Sheets (Parenthetical) - shares	Mar. 31, 2017	Dec. 31, 2016
Condensed Consolidated Balance Sheets [Abstract]
Capital account, interests outstanding	635,000,000	635,000,000

Business and Significant Accoun

Business and Significant Accounting Policies	3 Months Ended
	Mar. 31, 2017
Business And Significant Accounting Policies [Abstract]
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 that sell power in the north-central, eastern and western parts of Texas. Revenues from subsidiaries of Vistra (subsidiaries of TCEH until October 3, 2016 ) represented 23% of our total operating revenues for each of the three - month periods ended March 31, 2017 and 2016. 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 former wholly-owned, bankruptcy-remote financing subsidiary, Bondco, a variable interest entity through December 29, 2016, at which time it was dissolved. This financing subsidiary was organized for the limited purpose of issuing certain 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. 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, the Debtors commenced proceedings under Chapter 11 of the U.S. 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  These unaudited condensed financial statements should be read in conjunction with the audited financial statements and related notes included in the 2016 Form 10-K. In the opinion of Oncor management, all adjustments (consisting of normal recurring accruals) necessary for a fair presentation of the results of operations and financial position have been made. All intercompany items and transactions have been eliminated in consolidation. 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 U.S. 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.  Revenue Recognition  General  Oncor’s revenue is billed under tariffs approved by the PUCT and the majority of revenues are related to providing electric delivery service to consumers. Tariff rates are designed to recover the cost of providing electric delivery service including a reasonable rate of return on invested capital. Revenues are generally recognized when the underlying service has been provided in an amount prescribed by the related tariff.  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 February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-2 which created FASB Topic 842, Leases (Topic 842) . Topic 842 amends previous GAAP to require the balance sheet recognition of lease assets and liabilities for operating leases. We will be required to adopt Topic 842 by January 1, 2019 and do not expect to early adopt. Retrospective application to the 2017 and 2018 comparative periods presented will be required in the year of adoption. The recognition of any lease obligation on the balance sheet would be classified as long-term debt for GAAP purposes and would be defined as debt for our regulatory capital structure purposes ( s ee Note 8 for details). Although adoption of Topic 842 will affect our balance sheet and capitalization ratios, the impact is not expected to be material. We continue to evaluate the impact of Topic 842 on our financial statements.  Since May 2014, the FASB has issued ASU No. 2014-09, Revenue from Contracts with Customers along with other supplemental guidance (together, Topic 606). Topic 606 introduces new, increased requirements for disclosure of revenue in financial statements and guidance that are intended to eliminate inconsistencies in the recognition of revenue. We will be required to adopt Topic 606 by January 1, 2018 and do not expect to early adopt. Our revenues from customers are tariff-based and are designed to recover the cost of providing electric delivery service to customers including a reasonable rate of return on invested capital. Revenues are generally recognized when the underlying service has been provided in an amount prescribed by the related tariff. At this time, we do not expect the new guidance to change this pattern of recognition and therefore it is not expected to have a material effect on our reported results of operations, financial condition or cash flows. We continue to evaluate the application of the new guidance.  In March 2017, the FASB issued ASU 2017-07 Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost (ASU 2017-07). The new guidance will change how defined benefit plan costs are presented in the income statement. In addition, only the service cost component of net benefit cost will be eligible for capitalization as part of inventory or property, plant and equipment. We are required to adopt ASU 2017-07 effective January 1, 2018 and are currently evaluating the potential impact on our financial statements.

EFH Bankruptcy Proceedings

EFH Bankruptcy Proceedings	3 Months Ended
	Mar. 31, 2017
EFH Bankruptcy Proceedings [Abstract]
EFH BANKRUPTCY PROCEEDINGS	2. EFH BANKRUPTCY PROCEEDINGS  On the EFH Petition Date, EFH Corp. and the substantial majority of its direct and indirect subsidiaries at the time, including EFIH, EFCH and TCEH, commenced proceedings under Chapter 11 of the U.S. 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 1 and below for further information regarding the EFH Bankruptcy Proceedings and the proposed change in control of our indirect majority owner in connection with such proceedings.  The U.S. Bankruptcy Code automatically enjoined, or stayed, us from judicial or administrative proceedings or filing of other actions against our affiliates or their property to recover, collect or secure our claims arising prior to the EFH Petition Date. Following the EFH Petition Date, EFH Corp. received approval from the bankruptcy court to pay or otherwise honor certain prepetition obligations generally designed to stabilize its operations. Included in the approval were the obligations owed to us representing our prepetition electricity delivery fees. As of March 31, 2017, we had collected our prepetition receivables from the Texas Holdings Group of approximately $129 million. As discussed below, the Plan of Reorganization (defined below) provided for a spin-off of the TCEH Debtors from EFH Corp. As a result of this spin-off (Vistra Spin-Off), Vistra and its subsidiaries, including Luminant and TXU Energy, ceased to be affiliates of ours as of October 3, 2016.  The EFH Bankruptcy Proceedings continue to be a complex litigation matter and the full extent of potential impacts on us remain unknown. We will continue to evaluate our affiliate transactions and contingencies throughout the EFH Bankruptcy Proceedings to determine any risks and resulting impacts on our results of operations, financial statements and cash flows.  See Note 10 for details of Oncor’s related-party transactions with members of the Texas Holdings Group.  Potential Change in Indirect Ownership of Oncor  Below is a summary of certain matters relating to the potential change in indirect ownership of Oncor that may arise as a result of the EFH Bankruptcy Proceedings. See Note 2 to Financial Statements in our 2016 Form 10-K for additional information regarding these matters.  In May 2016, the Debtors filed a joint Plan of Reorganization (Plan of Reorganization) pursuant to Chapter 11 of the U.S. Bankruptcy Code and a related disclosure statement with the bankruptcy court. With respect to the EFH Debtors, the Plan of Reorganization, subject to certain conditions and required regulatory approvals, provides for, among other things, the reorganization of EFH Corp. and EFIH (Reorganized EFH) either pursuant to (a) an equity investment (which may be from existing creditors or third-party investors) or (b) pursuant to a standalone plan of reorganization, in which creditors receive shares of common stock of Reorganized EFH.  The Plan of Reorganization also provides that the confirmation and effective date of the Plan of Reorganization with respect to the TCEH Debtors may occur separate from, and independent of, the confirmation and effective date of the Plan of Reorganization with respect to the EFH Debtors. In this regard, the bankruptcy court confirmed the Plan of Reorganization with respect to the TCEH Debtors in August 2016, and it became effective by its terms, and the Vistra Spin-Off occurred, effective October 3, 2016.  In July 2016, (i) the EFH Debtors entered into a Plan Support Agreement (NEE Plan Support Agreement) with NEE to effect an agreed upon restructuring of the EFH Debtors pursuant to an amendment (NEE Amendment) to the Plan of Reorganization (as amended by the NEE Amendment and as subsequently amended, Amended EFH Debtor Plan) and (ii) EFH Corp. and EFIH entered into an Agreement and Plan of Merger (NEE Merger Agreement) with NEE and EFH Merger Co., LLC (Merger Sub), a wholly-owned subsidiary of NEE. Pursuant to the NEE Merger Agreement, at the effective time of the Amended EFH Debtor Plan with respect to the EFH Debtors, EFH Corp. would merge with and into Merger Sub (NEE Merger), with Merger Sub surviving as a wholly owned subsidiary of NEE. In August 2016, the EFH Debtors filed a motion seeking bankruptcy court approval of entry into the NEE Merger Agreement, a related termination fee and the NEE Plan Support Agreement. The NEE Merger Agreement includes various conditions precedent to consummation of the transactions contemplated thereby, including, among others, a condition that certain approvals and rulings be obtained, including from, among others, the PUCT and the IRS. The bankruptcy court approved EFH Corp. and EFIH’s entry into the NEE Merger Agreement, the related termination fee, and the NEE Plan Support Agreement in September 2016. The bankruptcy court approved the disclosure statement related to the Amended EFH Debtor Plan in January 2017 and confirmed the Amended EFH Debtor Plan in February 2017.  In October 2016, we entered into an Interest Purchase Agreement (OMI Agreement) with T & D Equity Acquisition, LLC, a wholly-owned subsidiary of NEE (T&D Equity Acquisition) and Investment LLC pursuant to which T&D Equity Acquisition would purchase the 1,396,008 limited liability company interests of Oncor (representing approximately 0.22% of the outstanding equity of Oncor) that Investment LLC owns in exchange for a purchase price of approximately $27 million. The OMI Agreement contains various conditions precedent to consummation of the transactions contemplated thereby, including the consummation of the transactions contemplated by the NEE Merger Agreement.  Also in October 2016, an affiliate of NEE entered into an Agreement and Plan of Merger (the TTI Merger Agreement) with Texas Transmission Holdings Corporation (the parent of Texas Transmission) and certain of its affiliates to purchase Texas Transmission’s 19.75% equity interest in Oncor for approximately $2.4 billion. The parties have agreed to use their best efforts to have the TTI Merger Agreement close contemporaneously with the NEE Merger. The TTI Merger Agreement also contains various conditions precedent to consummation of the transactions contemplated thereby, including a requirement that EFH Corp., subject to bankruptcy court approval, waive its rights of first refusal under the Investor Rights Agreement to purchase Texas Transmission’s 19.75% equity interest in Oncor.  Following the execution and delivery of the NEE Merger Agreement, EFIH requested, pursuant to the NEE Merger Agreement, that Oncor Holdings and Oncor enter into a letter agreement (NEE Letter Agreement) with NEE and Merger Sub. The NEE Letter Agreement was executed in August 2016 and sets forth certain rights and obligations of the Oncor Ring-Fenced Entities, NEE and Merger Sub to cooperate in the manner set forth therein with respect to initial steps to be taken in connection with the acquisition of Reorganized EFH (EFH Acquisition) and the other transactions described in the NEE Merger Agreement. The NEE Letter Agreement is not intended to give NEE or Merger Sub, directly or indirectly, the right to control or direct the operations of any of the Oncor Ring-Fenced Entities prior to the receipt of all approvals required by the bankruptcy court, the PUCT and other governmental entities and the consummation of the EFH Acquisition and related transactions (if and when such transactions are consummated). In addition, Oncor Holdings and Oncor have not endorsed or approved any restructuring involving Oncor Holdings or Oncor or any other transaction proposed by NEE or Merger Sub involving Oncor Holdings or Oncor.  As discussed under “Regulatory Matters Related to the EFH Bankruptcy Proceedings” below, on April 13, 2017, the PUCT denied the joint application in PUCT Docket No. 46238, which sought certain regulatory approvals with respect to the transactions contemplated by the Amended EFH Debtor Plan. Following the PUCT’s denial of the joint application, the parties to the NEE Letter Agreement agreed as of April 17, 2017 to abate the parties’ obligations under the NEE Letter Agreement for 60 days. The abatement does not apply to the provisions of Section 17 of the NEE Letter Agreement, including Oncor Holdings and Oncor’s rights to terminate the NEE Letter Agreement, which shall remain operative and in effect during the abatement period.  We cannot predict the ultimate outcome of the EFH Bankruptcy Proceedings, including whether the transactions contemplated by the Amended EFH Debtor Plan, including the EFH Acquisition, will (or when they will) close. Although the Amended EFH Debtor Plan has been confirmed by the bankruptcy court, there remain conditions and uncertainties relating to the Amended EFH Debtor Plan becoming effective and the consummation of the EFH Acquisition, including, without limitation, the ability to obtain required regulatory approvals from the PUCT, as described below under “–Regulatory Matters Related to EFH Bankruptcy Proceedings.”  As a result, we remain unable to predict how any reorganization of EFH Corp. and EFIH ultimately will impact Oncor or what form any change in indirect ownership of Oncor may take.  Regulatory Matters Related to EFH Bankruptcy Proceedings  In September 2015, Oncor and the Hunt Investor Group filed in PUCT Docket No. 45188 a joint application with the PUCT seeking certain regulatory approvals with respect to transactions contemplated by a plan of reorganization in the EFH Bankruptcy Proceedings. In March 2016, the PUCT issued an order conditionally approving the joint application. In April 2016, the Hunt Investor Group and certain interveners in PUCT Docket No. 45188 filed motions for rehearing and in May 2016, the PUCT denied such motions and the order became final. In May 2016, the plan of reorganization and related merger and purchase agreement that contemplated the transactions in PUCT Docket No. 45188 were terminated. The Hunt Investor Group filed a petition with the Travis County District Court in June 2016 seeking review of the order. We cannot predict the results of the review or the ultimate disposition of PUCT Docket No. 45188, particularly in light of the termination of the plan of reorganization related to the application filed in such docket.  In connection with PUCT Docket No. 45188, certain cities that have retained original jurisdiction over electric utility rates passed resolutions directing Oncor to file rate review proceedings. In connection with those resolutions, counsel for those cities notified Oncor that they expected Oncor to make a rate filing to comply with their resolutions on or before March 17, 2017. That filing was made with the PUCT and original jurisdiction cities on March 17, 2017. For more information, see Note 3 – “2017 Rate Review (PUCT Docket No. 46957).”  The NEE Merger Agreement contemplated that Oncor and NEE file a joint application with the PUCT seeking certain regulatory approvals with respect to the transactions contemplated by the Amended EFH Debtor Plan. Oncor and NEE filed that joint application in PUCT Docket No. 46238 in October 2016. The PUCT denied the application on April 13, 2017. The parties have until May 8, 2017 to file a motion for rehearing with the PUCT. We cannot predict the result of PUCT Docket No. 46238 or the ultimate outcome of the EFH Bankruptcy Proceedings, including whether the transactions contemplated by the Amended EFH Debtor Plan, including the EFH Acquisition, will (or when they will) close.  Settlement Agreement  In connection with the EFH Bankruptcy Proceedings, the EFH Debtors and various creditor parties entered into a settlement agreement (the Settlement Agreement) in August 2015 (as amended in September 2015) to compromise and settle, among other things (a) intercompany claims among the EFH Debtors, (b) claims and causes of actions against holders of first lien claims against TCEH and the agents under the TCEH Senior Secured Facilities, (c) claims and causes of action against holders of interests in EFH Corp. and certain related entities and (d) claims and causes of action against each of the EFH Debtors’ current and former directors, the Sponsor Group, managers and officers and other related entities. The Settlement Agreement contemplates a release of such claims upon approval of the Settlement Agreement by the bankruptcy court, which approval was obtained in December 2015.  The Settlement Agreement settles substantially all inter-debtor claims through the effective date of the Settlement Agreement. These settled claims include potentially contentious inter-debtor claims, including various potential avoidance actions and claims arising under numerous debt agreements, tax sharing agreements, and contested property transfers. The release provisions of the Settlement Agreement took effect immediately upon the entry of the bankruptcy court order approving the Settlement Agreement. In this regard, substantially all of the potential affiliate claims, derivative claims and other types of disputes among affiliates (including claims against Oncor) have been resolved by bankruptcy court order. Accordingly, we believe the Settlement Agreement resolves all affiliate claims against Oncor and its assets existing as of the effective date of the Settlement Agreement. 

Regulatory Matters

Regulatory Matters	3 Months Ended
	Mar. 31, 2017
Regulatory Matters [Abstract]
REGULATORY MATTERS	3. REGULATORY MATTERS  Change in Control Reviews  See “Regulatory Matters Related to EFH Bankruptcy Proceedings” in Note 2 to Financials Statements.  2017 Rate Review (PUCT Docket No. 46957)  In response to resolutions passed by numerous cities with original jurisdiction over electric utility rates in 2016, we filed rate review proceedings with the PUCT and original jurisdiction cities in our service territory on March 17, 2017 based on a January 1, 2016 to December 31, 2016 test year. If our proposed tariffs are adopted as filed, our annual revenue would increase by approximately $320 million. A procedural schedule has been agreed to by the parties to the case, which would result in PUCT hearings being held July 31, 2017 to August 9, 2017. Oncor has agreed to extend the requested effective date of the rate case increase such that the jurisdictional deadline for the PUCT to act has been extended to November 30, 2017.  We are involved in various other regulatory proceedings in the normal course of business, the ultimate resolution of which, in the opinion of management, should not have a material effect upon our financial position, results of operations or cash flows.  See Note 3 to Financial Statements in our 2016 Form 10-K for additional information regarding regulatory matters.

Regulatory Assets and Liabiliti

Regulatory Assets and Liabilities	3 Months Ended
	Mar. 31, 2017
Regulatory Assets and Liabilities [Abstract]
REGULATORY ASSETS AND LIABILITIES	4. REGULATORY ASSETS AND LIABILITIES  Recognition of regulatory assets and liabilities and the amortization periods over which they are expected to be recovered or refunded through rate regulation reflect the decisions of the PUCT. Components of our regulatory assets and liabilities are provided in the table below. Amounts not earning a return through rate regulation are noted.   Remaining Rate Recovery/Amortization Period at Carrying Amount At  March 31, 2017 March 31, 2017 December 31, 2016   Regulatory assets:  Employee retirement costs being amortized 3 years $ 19 $ 23  Unrecovered employee retirement costs incurred since the last rate review period (b) To be determined 335 327  Employee retirement liability (a)(b)(c) To be determined 835 849  Self-insurance reserve (primarily storm recovery costs) being amortized 3 years 56 64  Unrecovered self-insurance reserve incurred since the last rate review period (b) To be determined 369 367  Securities reacquisition costs (post-industry restructure) Lives of related debt 13 13  Deferred conventional meter and metering facilities depreciation Largely 4 years 73 78  Under-recovered AMS costs To be determined 209 205  Under-recovered wholesale transmission service expense (a) 1 year or less 6 -  Energy efficiency performance bonus (a) 1 year or less 7 10  Other regulatory assets Various 37 38  Total regulatory assets 1,959 1,974   Regulatory liabilities:  Estimated net removal costs Lives of related assets 857 819  Investment tax credit and protected excess deferred taxes Various 9 10  Over-recovered wholesale transmission service expense (a) 1 year or less - 10  Other regulatory liabilities Various 23 17  Total regulatory liabilities 889 856  Net regulatory asset $ 1,070 $ 1,118 ____________ (a) Not earning a return in the regulatory rate-setting process. (b) Recovery is specifically authorized by statute or by the PUCT, subject to reasonableness review. (c) Represents unfunded liabilities recorded in accor dance with pension and OPEB accounting standards.

Borrowings Under Credit Facilit

Borrowings Under Credit Facilities	3 Months Ended
	Mar. 31, 2017
Borrowings Under Credit Facilities [Abstract]
BORROWINGS UNDER CREDIT FACILITIES	5. BORROWINGS UNDER CREDIT FACILITIES  At March 31, 2017 , we had a $2.0 billion secured revolving credit facility to be used for working capital and general corporate purposes, issuances of letters of credit and support for any commercial paper issuances. In October 2016, we exercised the second of two one -year extensions available to us and extended the term of the revolving credit facility to October 2018 . The terms of the revolving credit facility allow us to request an increase in our borrowing capacity of $100 million in the aggregate provided certain conditions are met, including lender approval.  Borrowings under the revolving credit facility are classified as short-term on the balance sheet and are secured equally and ratably with all of our other secured indebtedness by a first priority lien on property we acquired or constructed for the transmission and distribution of electricity. The property is mortgaged under the Deed of Trust.  At March 31, 2017 , we had outstanding borrowings under the revolving credit facility totaling $880 million with an interest rate of 1.94% and outstanding letters of credit totaling $9 million. At December 31, 2016 , we had outstanding borrowings under the revolving credit facility totaling $789 million with an interest rate of 1.72% and outstanding letters of credit totaling $7 million.  Borrowings under the revolving credit facility bear interest at per annum rates equal to, at our option, (i) LIBOR plus a spread ranging from 1.00% to 1.75% depending on credit ratings assigned to our senior secured non-credit enhanced long-term debt or (ii) an alternate base rate (the highest of (1) the prime rate of JPMorgan Chase, (2) the federal funds effective rate plus 0.50% , and (3) daily one-month LIBOR plus 1.00% ) plus a spread ranging from 0.00% to 0.75% depending on credit ratings assigned to our senior secured non-credit enhanced long-term debt. At March 31, 2017 , all outstanding borrowings bore interest at LIBOR plus 1.00% . Amounts borrowed under the revolving credit facility, once repaid, can be borrowed again from time to time.  An unused commitment fee is payable quarterly in arrears and upon termination or commitment reduction at a rate equal to 0.100% to 0.275% (such spread depending on certain credit ratings assigned to our senior secured debt) of the daily unused commitments under the revolving credit facility. Letter of credit fees on the stated amount of letters of credit issued under the revolving credit facility are payable to the lenders quarterly in arrears and upon termination at a rate per annum equal to the spread over adjusted LIBOR. Customary fronting and administrative fees are also payable to letter of credit fronting banks. At March 31, 2017 , letters of credit bore interest at 1.20% , and a commitment fee (at a rate of 0.10% per annum) was payable on the unfunded commitments under the revolving credit facility, each based on our current credit ratings.  Subject to the limitations described below, borrowing capacity available under the revolving credit facility at March 31, 2017 and December 31, 2016 was $1.111 billion and $1.204 billion, respectively. Generally, our indentures and revolving credit facility limit the incurrence of other secured indebtedness except for indebtedness secured equally and ratably with the indentures and revolving credit facility and certain permitted exceptions. As described further in Note 6, the Deed of Trust permits us to secure indeb tedness (including borrowings under our revolving credit facility) with the lien of the Deed of Trust. At March 31, 2017 , the available borrowing capacity of the revolving credit facility could be fully drawn.  The revolving credit facility contains customary covenants for facilities of this type, restricting, subject to certain exceptions, us and our subsidiaries from, among other things: incurring additional liens; entering into mergers and consolidations; and sales of substantial assets. In addition, the revolving credit facility requires that we maintain a consolidated senior debt-to-capitalization ratio of no greater than 0.65 to 1.00 and observe certain customary reporting requirements and other affirmative covenants. For purposes of the ratio, debt is calculated as indebtedness defined in the revolving credit facility (principally, the sum of long-term debt, any capital leases, short-term debt and debt due currently in accordance with GAAP). Capitalization is calculated as membership interests determined in accordance with GAAP plus indebtedness described above. At March 31, 2017, we were in compli ance with this covenant and with all other covenants . 

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2017
Long-Term Debt [Abstract]
LONG-TERM DEBT	6. LONG-TERM DEBT  Our long-term debt is s ecured by a first priority lien on certain transmission and distribution assets equally and ratably with all of Oncor’s other secured indebtedness. See “Deed of Trust” below for additional information. At March 31, 2017 and December 31, 2016 , our long-term debt consisted of the following:   March 31, December 31,  2017 2016   5.000% Fixed Senior Notes due September 30, 2017 $ 324 $ 324  6.800% Fixed Senior Notes due September 1, 2018 550 550  2.150% Fixed Senior Notes due June 1, 2019 250 250  5.750% Fixed Senior Notes due September 30, 2020 126 126  4.100% Fixed Senior Notes due June 1, 2022 400 400  7.000% Fixed Debentures due September 1, 2022 800 800  2.950% Fixed Senior Notes due April 1, 2025 350 350  7.000% Fixed Senior Notes due May 1, 2032 500 500  7.250% Fixed Senior Notes due January 15, 2033 350 350  7.500% Fixed Senior Notes due September 1, 2038 300 300  5.250% Fixed Senior Notes due September 30, 2040 475 475  4.550% Fixed Senior Notes due December 1, 2041 400 400  5.300% Fixed Senior Notes due June 1, 2042 500 500  3.750% Fixed Senior Notes due April 1, 2045 550 550  Unamortized discount and debt issuance costs (34) (36)  Less amount due currently (324) (324)  Long-term debt, less amounts due currently 5,517 5,515  Deed of Trust  Our secured indebtedness, including the revolving credit facility described in Note 5, is secured equally and ratably by a first priority lien on property we acquired or constructed for the transmission and distribution of electricity. The property is mortgaged under the Deed of Trust. The Deed of Trust permits us to secure indebtedness (including borrowings under our revolving credit facility) with the lien of the Deed of Trust up to the aggregate of (i) the amount of available bond credits, and (ii) 85% of the lower of the fair value or cost of certain property additions that could be certified to the Deed of Trust collateral agent. At March 31, 2017 , the amount of available bond credits was $2.532 billion and the amount of future debt we could secure with property additions, subject to those property additions being certified to the Deed of Trust collateral agent, was $1.792 billion.  Fair Value of Long-Term Debt  At March 31, 2017 and December 31, 2016 , the estimated fair value of our long-term debt (including current maturities, if any) totaled $6.736 billion and $6.751 billion, respectively, and the carrying amount totaled $5.841 billion and $5.839 billion, respectively. The fair value is estimated using observable market data, representing Level 2 valuations under accounting standards related to the determination of fair value.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2017
Commitments and Contingencies [Abstract]
COMMITMENTS AND CONTINGENCIES	7. COMMITMENTS AND CONTINGENCIES  EFH Bankruptcy Proceedings  On the EFH Petition Date, the Debtors commenced the EFH Bankruptcy Proceedings . T he Oncor Ring-Fenced Entities are not parties to the EFH Bankruptcy Proceedings. See Notes 2 and 10 for a discussion of the potential impacts on us as a result of the EFH Bankruptcy Proceedings and our related-party transactions involving members of the Texas Holdings Group, respectively. Legal/Regulatory Proceedings  We are involved in various legal and administrative proceedings in the normal course of business, the ultimate resolution of which, in the opinion of management, should not have a material effect upon our financial position, results of operations or cash flows. See Note 3 in this report and Note 8 to Financial Statements in our 2016 Form 10-K for additional information regarding our legal and regulatory proceedings. 

Membership Interests

Membership Interests	3 Months Ended
	Mar. 31, 2017
Membership Interests [Abstract]
MEMBERSHIP INTERESTS	8. MEMBERSHIP INTERESTS  Cash Distributions   Distributions are limited by our required regulatory capital structure to be at or below the assumed debt-to-equity ratio established periodically by the PUCT for ratemaking purposes, which is currently set at 60% debt to 40% equity. At March 31, 2017, $89 million was available for distribution to our members as our regulatory capitalization ratio was 59.5% debt to 40.5% equity. The PUCT has the authority to determine what types of debt and equity are included in a utility’s debt-to-equity ratio. For purposes of this ratio, debt is calculated as long-term debt plus unamortized gains on reacquired debt less unamortized issuance expenses, premiums and losses on reacquired debt. Equity is calculated as membership interests determined in accordance with GAAP, excluding the effects of acquisition accounting (which included recording the initial goodwill and fair value adjustments and subsequent related impairments and amortization).   On April 2 6 , 201 7 , our board of directors declared a cash distribution of $86 million, which was paid to our members on April 27, 201 7. In March 2017, our board of directors declared, and we paid, a cash distribution of $86 million to our members.  Membership Interests  The following table present s the changes to membership interests during the three months ended March 31, 2017 and 2016 :    Capital Accounts Accumulated Other Comprehensive Income (Loss) Total Membership Interests   Balance at December 31, 2016 $ 7,822 $ (111) $ 7,711  Net income 73 - 73  Distributions (86) - (86)  Net effects of cash flow hedges (net of tax) - 1 1  Balance at March 31, 2017 $ 7,809 $ (110) $ 7,699   Balance at December 31, 2015 $ 7,621 $ (113) $ 7,508  Net income 81 - 81  Distributions (56) - (56)  Net effects of cash flow hedges (net of tax) - - -  Balance at March 31, 2016 $ 7,646 $ (113) $ 7,533  Accumulated Other Comprehensive Income (Loss)  The following table present s the changes to accumulated other comprehensive income (loss) for the three months ended March 31, 2017 and 2016 :   Cash Flow Hedges – Interest Rate Swap Defined Benefit Pension and OPEB Plans Accumulated Other Comprehensive Income (Loss)   Balance at December 31, 2016 $ (20) $ (91) $ (111)  Defined benefit pension plans (net of tax) - - -  Amounts reclassified from accumulated other comprehensive income (loss) and reported in interest expense and related charges 1 - 1  Balance at March 31, 2017 $ (19) $ (91) $ (110)   Balance at December 31, 2015 $ (22) $ (91) $ (113)  Defined benefit pension plans (net of tax) - - -  Amounts reclassified from accumulated other comprehensive income (loss) and reported in interest expense and related charges - - -  Balance at March 31, 2016 $ (22) $ (91) $ (113) 

Pension and OPEB Plans

Pension and OPEB Plans	3 Months Ended
	Mar. 31, 2017
Pension And OPEB Plans [Abstract]
PENSION AND OPEB PLANS	9. PENSION AND OPEB PLANS  Pension Plans  We sponsor the Oncor Retirement Plan and also have liabilities under the Vistra Retirement Plan , both of which are qualified pension plans under Section 401(a) of the Internal Revenue Code of 1986, as amended, and are subject to the provisions of ERISA. Employees do not contribute to either plan. We also have a supplemental pension plan for certain employees whose retirement benefits cannot be fully earned under the qualified retirement plans. See Note 10 to Financial Statements in our 2016 Form 10-K for additional information regarding pension plans.  Oncor OPEB Plan  The Oncor OPEB Plan covers our eligible current and future retirees as well as certain eligible retirees of EFH Corp. /Vistra whose employment included service with both Oncor (or a predecessor regulated electric business) and a non-regulated business of EFH Corp. Vistra is solely responsible for its portion of the liability for retiree benefits related to those retirees. As we are not responsible for Vistra’s portion of the Oncor OPEB Plan’s unfunded liability, that amount is not reported on our balance sheet. See Note 10 to Financial Statements in our 2016 Form 10-K for additional information.  Pension and OPEB Costs  Our net costs related to pension plans and the Oncor OPEB P lan for the three months ended March 31, 2017 and 2016 were comprised of the following:   Three Months Ended March 31,  2017 2016   Components of net allocated pension costs:  Service cost $ 6 $ 6  Interest cost 33 34  Expected return on assets (29) (31)  Amortization of net loss 11 10  Net pension costs 21 19  Components of net OPEB costs:  Service cost 2 2  Interest cost 12 12  Expected return on assets (2) (2)  Amortization of prior service cost (5) (5)  Amortization of net loss 8 8  Net OPEB costs 15 15  Total net pension and OPEB costs 36 34  Less amounts deferred principally as property or a regulatory asset (25) (25)  Net amounts recognized as expense $ 11 $ 9  The discount rates reflected in net pension and OPEB costs in 2017 are 4.04% , 4.28% and 4.35% for the Oncor Retirement Plan, the Vistra Retirement Plan and the Oncor OPEB Plan, respectively. The expected return on pension and OPEB plan assets reflected in the 2017 cost amounts are 5.17% , 5.13% and 6.10% for the Oncor Retirement Plan, the Vistra Retirement Plan and the Oncor OPEB Plan, respectively.  Pension and OPEB Plans Cash Contributions  We made cash contribution s to the pension plans and Oncor OPEB P lan of $1 million and $8 million, respectively, during the three months ended March 31, 2017. We expect to make additional cash contributions to the pension plans and Oncor OPEB Plan of $148 million and $23 million, respectively, during the remainder of 201 7 . Our aggregate pension plans and Oncor OPEB Plan funding is expected to total approximately $586 million and $153 million, respectively, in the 201 7 to 202 1 period based on the latest actuarial projections.

Related-Party Transactions

Related-Party Transactions	3 Months Ended
	Mar. 31, 2017
Related-Party Transactions [Abstract]
RELATED-PARTY TRANSACTIONS	10. RELATED-PARTY TRANSACTIONS  The following represent our significant related-party transactions at March 31, 2017 . See Note 2 for additional information regarding related-party contingencies resulting from the EFH Bankruptcy Proceedings and information regarding the Vistra Spin-Off. As a result of the Vistra Spin-Off, Vistra and its subsidiaries, including Luminant and TXU Energy, ceased to be related parties as of October 3, 2016.  · We recorded revenue from TCEH, principally for electricity delivery fees, which totaled $220 million for the three months ended March 31, 2016. The fees are based on rates regulated by the PUCT that apply to all REPs.  · EFH Corp. subsidiaries charge d us for certain administrative services at cost. Our payments to EFH Corp. subsidiaries for administrative services, which are primarily reported in operation and maintenance expenses, tota led $1 million for the three months ended March 31, 2016. We also charge d each other for shared facilities at cost. Our payments to EFH Corp. for shared facilities totaled $1 m i llion for the three month s ended March 31, 2016 . Payments we received from EFH Corp. subsidiaries related to shared facilities totaled less than $1 m illion for the three month s ended March 31, 2016.  · We are not a member of EFH Corp.’s consolidated tax group, but EFH Corp.’s consolidated federal income tax return includes EFH Corp.’s portion of our results due to EFH Corp.’s equity ownership in us. Under the terms of a tax sharing agreement among us, Oncor Holdings, Texas Transmission, Investment LLC and EFH Corp., we are generally obligated to make payments to Texas Transmission, Investment LLC and EFH Corp., pro rata in accordance with their respective membership interests, in an aggregate amount that is substantially equal to the amount of federal income taxes that we would have been required to pay if we were filing our own corporate income tax return. For periods prior to the tax sharing agreement (entered into in October 2007 and amended and restated in November 2008), we are responsible for our share, if any, of redetermined tax liability for the EFH Corp. consolidated tax group. EFH Corp. also includes our results in its consolidated Texas margin tax payments, which are accounted for as income taxes and calculated as if we were filing our own return. See discussion in Note 1 to Financial Statements in our 2016 Form 10-K under “Income Taxes.” Under the “in lieu of” tax concept, all in lieu of tax assets and tax liabilities represent amounts that will eventually be settled with our members. In the unlikely event such amounts are not paid under the tax sharing agreement, it is probable that this regulatory liability will continue to be included in Oncor’s rate setting processes.  Amounts payable to (receivable from) members related to income taxes under the tax sharing agreement and reported on our balance sheet consisted of the following:   At March 31, 2017 At December 31, 2016  EFH Corp. Texas Transmission Total EFH Corp. Texas Transmission Total   Federal income taxes receivable $ (1) $ (5) $ (6) $ (62) $ (18) $ (80)  Texas margin taxes payable 25 - 25 20 - 20  Net payable (receivable) $ 24 $ (5) $ 19 $ (42) $ (18) $ (60)  Cash receipts from members related to federal income taxes for the three months ended March 31, 2017 totaled $135 million from EFH Corp. and $15 million from Texas Transmission.  · Related parties of the Sponsor Group have (1) sold, acquired or participated in the offerings of our debt or debt securities in open market transactions or through loan syndications, and (2) performed various financial advisory, dealer, commercial banking and investment banking services for us and certain of our affiliates for which they have received or will receive customary fees and expenses, and may from time to time in the future participate in any of the items in (1) and (2) above. Also, as of March 31, 2017, 16.6% of the equity in an existing vendor of the company was held by a member of the Sponsor Group. During 2017 and 2016, this vendor performed transmission and distribution system construction and maintenance services for us. Cash payments were made for such services to this vendor totaling $45 million dollars for the three months ended March 31, 2017, of which approximately $42 million was capitalized and $3 million was recor ded as an operation and maintenance expense. At March 31, 2017, we had outstanding trade payables to this vendor of $9 million.  See Note 8 for information regarding distributions to members and Note 9 for information regarding our participation in the EFH Corp. pension plan and transactions with EFH Corp. involving employee benefit matters.

Supplementary Financial Informa

Supplementary Financial Information	3 Months Ended
	Mar. 31, 2017
Supplementary Financial Information [Abstract]
SUPPLEMENTARY FINANCIAL INFORMATION	11. SUPPLEMENTARY FINANCIAL INFORMATION  Major Customers  Revenues from subsidiaries of Vistra ( subsidiaries of TCEH until October 3, 2016) represented 23% of our total operating revenues for each of the three-month periods ended March 31, 2017 and 2016. Revenues from REP subsidiaries of another nonaffiliated entity, collectively represented 18% and 16% of total operating revenues for each of the three months ended March 31, 2017 and 2016, respectively. No other customer represented 10% or more of our total operating revenues.  Other Income and ( Deductions )   Three Months Ended March 31,  2017 2016   Professional fees $ (5) $ (4)  Non-recoverable pension and OPEB (Note 9) (1) (1)  Other 2 -  Total other income and (deductions) - net $ (4) $ (5)  Interest Expense and Related Charges   Three Months Ended March 31,  2017 2016   Interest $ 86 $ 85  Amortization of debt issuance costs and discounts 1 1  Less allowance for funds used during construction – capitalized interest portion (2) (2)  Total interest expense and related charges $ 85 $ 84  Trade Accounts and Other Receivables  Trade accounts and other receivables reported on our balance sheet consisted of the following:   At March 31, At December 31,  2017 2016   Gross trade accounts and other receivables $ 508 $ 548  Allowance for uncollectible accounts (3) (3)  Trade accounts receivable – net $ 505 $ 545  At March 31, 2017 and December 31, 2016, REP subsidiaries of a nonaffiliated entity collectively represented approximately 14% and 15% of the trade accounts receivable amount, respectively. At March 31, 2017 and December 31, 2016 , REP subsidiaries of a nother nonaffiliated entity collectively represented approximately 11% and 12% of the trade accounts receivable amount, respectively.  Under a PUCT rule relating to the Certification of Retail Electric Providers, write-offs of uncollectible amounts owed by nonaffiliated REPs are deferred as a regulatory asset.  Investments and Other Property  Investments and other property reported on our balance sheet consisted of the following:   At March 31, At December 31,  2017 2016   Assets related to employee benefit plans, including employee savings programs $ 101 $ 98  Land and other investments 2 2  Total investments and other property $ 103 $ 100  Property, Plant and Equipment  Property, plant and equipment reported on our balance sheet consisted of the following:   At March 31, At December 31,  2017 2016   Total assets in service $ 20,385 $ 20,234  Less accumulated depreciation 6,935 6,836  Net of accumulated depreciation 13,450 13,398  Construction work in progress 649 416  Held for future use 15 15  Property, plant and equipment – net $ 14,114 $ 13,829  Intangible Assets  Intangible assets (other than goodwill) reported on our balance sheet as part of property, plant and equipment consisted of the following:   At March 31, 2017 At December 31, 2016  Gross Gross  Carrying Accumulated Carrying Accumulated  Amount Amortization Net Amount Amortization Net   Identifiable intangible assets subject to amortization:  Land easements $ 494 $ 96 $ 398 $ 491 $ 94 $ 397  Capitalized software 476 339 137 470 326 144  Total $ 970 $ 435 $ 535 $ 961 $ 420 $ 541  A ggregate amortization expense for intangible assets totaled $15 million and $16 milli on for the three months ended March 31, 2017 and 2016, respectively. The estimated aggregate amortization expense for each of the next five fiscal years is as follows:   Year Amortization Expense   2017 $ 57  2018 51  2019 48  2020 47  2021 47  At both March 31, 2017 and December 31, 2016 , goodwill totaling $ 4.1 billion was reported on our balance sheet. None of this goodwill is being deducted for tax purposes.  Employee Benefit Obligations and Other  Employee benefit obligations and other reported on our balance sheet consisted of the following:   At March 31, At December 31,  2017 2016   Retirement plans and other employee benefits $ 2,091 $ 2,092  Uncertain tax positions (including accrued interest) 3 3  Investment tax credits 12 12  Other 70 61  Total employee benefit obligations and other $ 2,176 $ 2,168  Supplemental Cash Flow Information   Three Months Ended March 31,  2017 2016   Cash payments (receipts) related to:  Interest $ 99 $ 98  Less capitalized interest (2) (2)  Interest payments (net of amounts capitalized) $ 97 $ 96   Amount in lieu of income taxes:  Federal $ (150) $ -   Noncash construction expenditures (a) $ 133 $ 82 _____________ (a) Represents end-of-period accruals.

Business and Significant Acco19

Business and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2017
Business And Significant Accounting Policies [Abstract]
Description Of Business	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 that sell power in the north-central, eastern and western parts of Texas. Revenues from subsidiaries of Vistra (subsidiaries of TCEH until October 3, 2016 ) represented 23% of our total operating revenues for each of the three - month periods ended March 31, 2017 and 2016. 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 former wholly-owned, bankruptcy-remote financing subsidiary, Bondco, a variable interest entity through December 29, 2016, at which time it was dissolved. This financing subsidiary was organized for the limited purpose of issuing certain 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. 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 Bankruptcy Proceedings	EFH Corp. Bankruptcy Proceedings  On the EFH Petition Date, the Debtors commenced proceedings under Chapter 11 of the U.S. 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	Basis of Presentation  These unaudited condensed financial statements should be read in conjunction with the audited financial statements and related notes included in the 2016 Form 10-K. In the opinion of Oncor management, all adjustments (consisting of normal recurring accruals) necessary for a fair presentation of the results of operations and financial position have been made. All intercompany items and transactions have been eliminated in consolidation. 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 U.S. dollars unless otherwise indicated.
Use Of Estimates	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.
Revenue Recognition	Revenue Recognition  General  Oncor’s revenue is billed under tariffs approved by the PUCT and the majority of revenues are related to providing electric delivery service to consumers. Tariff rates are designed to recover the cost of providing electric delivery service including a reasonable rate of return on invested capital. Revenues are generally recognized when the underlying service has been provided in an amount prescribed by the related tariff.  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	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	Changes in Accounting Standards  In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-2 which created FASB Topic 842, Leases (Topic 842) . Topic 842 amends previous GAAP to require the balance sheet recognition of lease assets and liabilities for operating leases. We will be required to adopt Topic 842 by January 1, 2019 and do not expect to early adopt. Retrospective application to the 2017 and 2018 comparative periods presented will be required in the year of adoption. The recognition of any lease obligation on the balance sheet would be classified as long-term debt for GAAP purposes and would be defined as debt for our regulatory capital structure purposes ( s ee Note 8 for details). Although adoption of Topic 842 will affect our balance sheet and capitalization ratios, the impact is not expected to be material. We continue to evaluate the impact of Topic 842 on our financial statements.  Since May 2014, the FASB has issued ASU No. 2014-09, Revenue from Contracts with Customers along with other supplemental guidance (together, Topic 606). Topic 606 introduces new, increased requirements for disclosure of revenue in financial statements and guidance that are intended to eliminate inconsistencies in the recognition of revenue. We will be required to adopt Topic 606 by January 1, 2018 and do not expect to early adopt. Our revenues from customers are tariff-based and are designed to recover the cost of providing electric delivery service to customers including a reasonable rate of return on invested capital. Revenues are generally recognized when the underlying service has been provided in an amount prescribed by the related tariff. At this time, we do not expect the new guidance to change this pattern of recognition and therefore it is not expected to have a material effect on our reported results of operations, financial condition or cash flows. We continue to evaluate the application of the new guidance.  In March 2017, the FASB issued ASU 2017-07 Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost (ASU 2017-07). The new guidance will change how defined benefit plan costs are presented in the income statement. In addition, only the service cost component of net benefit cost will be eligible for capitalization as part of inventory or property, plant and equipment. We are required to adopt ASU 2017-07 effective January 1, 2018 and are currently evaluating the potential impact on our financial statements.

Regulatory Assets and Liabili20

Regulatory Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2017
Regulatory Assets and Liabilities [Abstract]
Components Of Regulatory Assets And Liabilities	  Remaining Rate Recovery/Amortization Period at Carrying Amount At  March 31, 2017 March 31, 2017 December 31, 2016   Regulatory assets:  Employee retirement costs being amortized 3 years $ 19 $ 23  Unrecovered employee retirement costs incurred since the last rate review period (b) To be determined 335 327  Employee retirement liability (a)(b)(c) To be determined 835 849  Self-insurance reserve (primarily storm recovery costs) being amortized 3 years 56 64  Unrecovered self-insurance reserve incurred since the last rate review period (b) To be determined 369 367  Securities reacquisition costs (post-industry restructure) Lives of related debt 13 13  Deferred conventional meter and metering facilities depreciation Largely 4 years 73 78  Under-recovered AMS costs To be determined 209 205  Under-recovered wholesale transmission service expense (a) 1 year or less 6 -  Energy efficiency performance bonus (a) 1 year or less 7 10  Other regulatory assets Various 37 38  Total regulatory assets 1,959 1,974   Regulatory liabilities:  Estimated net removal costs Lives of related assets 857 819  Investment tax credit and protected excess deferred taxes Various 9 10  Over-recovered wholesale transmission service expense (a) 1 year or less - 10  Other regulatory liabilities Various 23 17  Total regulatory liabilities 889 856  Net regulatory asset $ 1,070 $ 1,118 ____________ (a) Not earning a return in the regulatory rate-setting process. (b) Recovery is specifically authorized by statute or by the PUCT, subject to reasonableness review. (c) Represents unfunded liabilities recorded in accor dance with pension and OPEB accounting standards.

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2017
Long-Term Debt [Abstract]
Schedule Of Long-Term Debt	  March 31, December 31,  2017 2016   5.000% Fixed Senior Notes due September 30, 2017 $ 324 $ 324  6.800% Fixed Senior Notes due September 1, 2018 550 550  2.150% Fixed Senior Notes due June 1, 2019 250 250  5.750% Fixed Senior Notes due September 30, 2020 126 126  4.100% Fixed Senior Notes due June 1, 2022 400 400  7.000% Fixed Debentures due September 1, 2022 800 800  2.950% Fixed Senior Notes due April 1, 2025 350 350  7.000% Fixed Senior Notes due May 1, 2032 500 500  7.250% Fixed Senior Notes due January 15, 2033 350 350  7.500% Fixed Senior Notes due September 1, 2038 300 300  5.250% Fixed Senior Notes due September 30, 2040 475 475  4.550% Fixed Senior Notes due December 1, 2041 400 400  5.300% Fixed Senior Notes due June 1, 2042 500 500  3.750% Fixed Senior Notes due April 1, 2045 550 550  Unamortized discount and debt issuance costs (34) (36)  Less amount due currently (324) (324)  Long-term debt, less amounts due currently 5,517 5,515 

Membership Interests (Tables)

Membership Interests (Tables)	3 Months Ended
	Mar. 31, 2017
Membership Interests [Abstract]
Schedule Of Changes To Membership Interests	  Capital Accounts Accumulated Other Comprehensive Income (Loss) Total Membership Interests   Balance at December 31, 2016 $ 7,822 $ (111) $ 7,711  Net income 73 - 73  Distributions (86) - (86)  Net effects of cash flow hedges (net of tax) - 1 1  Balance at March 31, 2017 $ 7,809 $ (110) $ 7,699   Balance at December 31, 2015 $ 7,621 $ (113) $ 7,508  Net income 81 - 81  Distributions (56) - (56)  Net effects of cash flow hedges (net of tax) - - -  Balance at March 31, 2016 $ 7,646 $ (113) $ 7,533 
Schedule Of Changes To Accumulated Other Comprehensive Income (Loss)	  Cash Flow Hedges – Interest Rate Swap Defined Benefit Pension and OPEB Plans Accumulated Other Comprehensive Income (Loss)   Balance at December 31, 2016 $ (20) $ (91) $ (111)  Defined benefit pension plans (net of tax) - - -  Amounts reclassified from accumulated other comprehensive income (loss) and reported in interest expense and related charges 1 - 1  Balance at March 31, 2017 $ (19) $ (91) $ (110)   Balance at December 31, 2015 $ (22) $ (91) $ (113)  Defined benefit pension plans (net of tax) - - -  Amounts reclassified from accumulated other comprehensive income (loss) and reported in interest expense and related charges - - -  Balance at March 31, 2016 $ (22) $ (91) $ (113) 

Pension and OPEB Plans (Tables)

Pension and OPEB Plans (Tables)	3 Months Ended
	Mar. 31, 2017
Pension And OPEB Plans [Abstract]
Schedule Of Pension And OPEB Plan Costs	  Three Months Ended March 31,  2017 2016   Components of net allocated pension costs:  Service cost $ 6 $ 6  Interest cost 33 34  Expected return on assets (29) (31)  Amortization of net loss 11 10  Net pension costs 21 19  Components of net OPEB costs:  Service cost 2 2  Interest cost 12 12  Expected return on assets (2) (2)  Amortization of prior service cost (5) (5)  Amortization of net loss 8 8  Net OPEB costs 15 15  Total net pension and OPEB costs 36 34  Less amounts deferred principally as property or a regulatory asset (25) (25)  Net amounts recognized as expense $ 11 $ 9 

Related-Party Transactions (Tab

Related-Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2017
Related-Party Transactions [Abstract]
Schedule Of Related Party Transactions	  At March 31, 2017 At December 31, 2016  EFH Corp. Texas Transmission Total EFH Corp. Texas Transmission Total   Federal income taxes receivable $ (1) $ (5) $ (6) $ (62) $ (18) $ (80)  Texas margin taxes payable 25 - 25 20 - 20  Net payable (receivable) $ 24 $ (5) $ 19 $ (42) $ (18) $ (60) 

Supplementary Financial Infor25

Supplementary Financial Information (Tables)	3 Months Ended
	Mar. 31, 2017
Supplementary Financial Information [Abstract]
Schedule Of Other Income And (Deductions)	  Three Months Ended March 31,  2017 2016   Professional fees $ (5) $ (4)  Non-recoverable pension and OPEB (Note 9) (1) (1)  Other 2 -  Total other income and (deductions) - net $ (4) $ (5) 
Schedule Of Interest Expense And Related Charges	  Three Months Ended March 31,  2017 2016   Interest $ 86 $ 85  Amortization of debt issuance costs and discounts 1 1  Less allowance for funds used during construction – capitalized interest portion (2) (2)  Total interest expense and related charges $ 85 $ 84 
Schedule Of Trade Accounts And Other Receivables	  At March 31, At December 31,  2017 2016   Gross trade accounts and other receivables $ 508 $ 548  Allowance for uncollectible accounts (3) (3)  Trade accounts receivable – net $ 505 $ 545 
Summary of Investments And Other Property	  At March 31, At December 31,  2017 2016   Assets related to employee benefit plans, including employee savings programs $ 101 $ 98  Land and other investments 2 2  Total investments and other property $ 103 $ 100 
Schedule Of Property, Plant And Equipment	  At March 31, At December 31,  2017 2016   Total assets in service $ 20,385 $ 20,234  Less accumulated depreciation 6,935 6,836  Net of accumulated depreciation 13,450 13,398  Construction work in progress 649 416  Held for future use 15 15  Property, plant and equipment – net $ 14,114 $ 13,829 
Schedule Of Intangible Assets	  At March 31, 2017 At December 31, 2016  Gross Gross  Carrying Accumulated Carrying Accumulated  Amount Amortization Net Amount Amortization Net   Identifiable intangible assets subject to amortization:  Land easements $ 494 $ 96 $ 398 $ 491 $ 94 $ 397  Capitalized software 476 339 137 470 326 144  Total $ 970 $ 435 $ 535 $ 961 $ 420 $ 541 
Schedule Of Estimated Aggregate Amortization Expenses	  Year Amortization Expense   2017 $ 57  2018 51  2019 48  2020 47  2021 47 
Schedule Of Employee Benefit Obligations And Other	  At March 31, At December 31,  2017 2016   Retirement plans and other employee benefits $ 2,091 $ 2,092  Uncertain tax positions (including accrued interest) 3 3  Investment tax credits 12 12  Other 70 61  Total employee benefit obligations and other $ 2,176 $ 2,168 
Schedule Of Supplemental Cash Flow Information	  Three Months Ended March 31,  2017 2016   Cash payments (receipts) related to:  Interest $ 99 $ 98  Less capitalized interest (2) (2)  Interest payments (net of amounts capitalized) $ 97 $ 96   Amount in lieu of income taxes:  Federal $ (150) $ -   Noncash construction expenditures (a) $ 133 $ 82 _____________ (a) Represents end-of-period accruals.

Business And Significant Acco26

Business And Significant Accounting Policies (Details) - entity	1 Months Ended	3 Months Ended
	Nov. 30, 2008	Mar. 31, 2017	Mar. 31, 2016
Business And Significant Accounting Polices [Line Items]
Number of entities that would possibly be bankrupt		1
Percentage of equity interest sold in the event of bankruptcy	19.75%
Oncor Holdings [Member]
Business And Significant Accounting Polices [Line Items]
Ownership		80.03%
Texas Transmission [Member]
Business And Significant Accounting Polices [Line Items]
Percentage of membership interest owned by non-controlling owners		19.75%
Sales [Member] | Vistra [Member]
Business And Significant Accounting Polices [Line Items]
Concentration risk percentage		23.00%	23.00%

EFH Bankruptcy Proceedings (Det

EFH Bankruptcy Proceedings (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Oct. 31, 2016	Mar. 31, 2017
OMI Agreement [Member]
Bankruptcy [Line Items]
Percent of outstanding equity interests required	0.22%
Limited liability company interests, shares	1,396,008
Limited liability company interests, value	$ 27,000
Texas Holdings Group [Member]
Bankruptcy [Line Items]
Amount receivable from related party		$ 129
Texas Holdings Group [Member] | TTI Merger Agreement [Member]
Bankruptcy [Line Items]
Percent of outstanding equity interests required		19.75%
Purchase price	$ 2,400

Regulatory Matters (Details)

Regulatory Matters (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Regulatory Matters [Abstract]
Increase (decrease) in revenue, upon adoption of proposed tariffs	$ 320

Regulatory Assets And Liabili29

Regulatory Assets And Liabilities (Components Of Regulatory Assets And Liabilities) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2017	Dec. 31, 2016
Regulatory Assets And Liabilities [Line Items]
Carrying Amount, Regulatory Assets		$ 1,959	$ 1,974
Carrying Amount, Regulatory Liabilities		889	856
Net regulatory asset		$ 1,070	1,118
Estimated Net Removal Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period		Lives of related assets
Carrying Amount, Regulatory Liabilities		$ 857	819
Investment Tax Credit and Protected Excess Deferred Taxes [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period		Various
Carrying Amount, Regulatory Liabilities		$ 9	10
Over-Recovered Wholesale Transmission Service Expense [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	[1]	1 year or less
Carrying Amount, Regulatory Liabilities	[1]		10
Other Regulatory Liabilities [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period		Various
Carrying Amount, Regulatory Liabilities		$ 23	17
Employee Retirement Costs Being Amortized [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period		3 years
Carrying Amount, Regulatory Assets		$ 19	23
Unrecovered Employee Retirement Costs Incurred Since The Last Rate Review Period [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	[2]	To be determined
Carrying Amount, Regulatory Assets	[2]	$ 335	327
Employee Retirement Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	[1],[2],[3]	To be determined
Carrying Amount, Regulatory Assets	[1],[2],[3]	$ 835	849
Self Insurance Reserve (Primarily Storm Recovery Costs) Being Amortized [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period		3 years
Carrying Amount, Regulatory Assets		$ 56	64
Unrecovered Self-Insurance Reserve Incurred Since The Last Rate Review Period [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	[2]	To be determined
Carrying Amount, Regulatory Assets	[2]	$ 369	367
Securities Reacquisition Costs (Post-Industry Restructure) [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period		Lives of related debt
Carrying Amount, Regulatory Assets		$ 13	13
Deferred Conventional Meter And Metering Facilities Depreciation [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period		Largely 4 years
Carrying Amount, Regulatory Assets		$ 73	78
Under-recovered AMS Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period		To be determined
Carrying Amount, Regulatory Assets		$ 209	205
Under-Recovered Wholesale Transmission Service Expense [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	[1]	1 year or less
Carrying Amount, Regulatory Assets	[1]	$ 6
Energy Efficiency Performance Bonus [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	[1]	1 year or less
Carrying Amount, Regulatory Assets	[1]	$ 7	10
Other Regulatory Assets [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period		Various
Carrying Amount, Regulatory Assets		$ 37	$ 38
[1]	Not earning a return in the regulatory rate-setting process.
[2]	Recovery is specifically authorized by statute or by the PUCT, subject to reasonableness review.
[3]	Represents unfunded liabilities recorded in accordance with pension and OPEB accounting standards.

Borrowings Under Credit Facil30

Borrowings Under Credit Facilities (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)item	Dec. 31, 2016USD ($)
Line of Credit Facility [Line Items]
Outstanding borrowing under the revolving credit facility	$ 880	$ 789
Outstanding borrowing, interest rate	1.94%	1.72%
Letters of credit	$ 9	$ 7
Commitment fee	0.10%
Borrowing capacity available under the credit facility	$ 1,111	$ 1,204
Maximum [Member]
Line of Credit Facility [Line Items]
Commitment fee	0.275%
Debt-to-capitalization ratio	1
Minimum [Member]
Line of Credit Facility [Line Items]
Commitment fee	0.10%
Debt-to-capitalization ratio	0.65
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Outstanding borrowing, interest rate	1.20%
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 2,000
Number of revolving credit facilities extension options | item	2
Extension period for revolving line of credit	1 year
Expiration of revolving credit facility	Oct. 31, 2018
Additional increase in borrowing capacity amount	$ 100
London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Spread over variable rate	1.00%
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Spread over variable rate	1.75%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Spread over variable rate	1.00%
Federal Funds Effective Rate [Member]
Line of Credit Facility [Line Items]
Spread over variable rate	0.50%
One-Month London Interbank Offered Rate [Member]
Line of Credit Facility [Line Items]
Spread over variable rate	1.00%
One-Month London Interbank Offered Rate [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Spread over variable rate	0.75%
One-Month London Interbank Offered Rate [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Spread over variable rate	0.00%

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Long-Term Debt [Line Items]
Percentage of fair value of cost of property additions certified to the Deed of Trust collateral agent	85.00%
Available bond credits	$ 2,532
Future debt subject to property additions to the Deed of Trust	1,792
Estimated fair value of our long-term debt including current maturities	6,736	$ 6,751
Carrying amount	$ 5,841	$ 5,839
3.750% Fixed Senior Notes due April 1, 2045 [Member]
Long-Term Debt [Line Items]
Interest percentage	3.75%	3.75%
Due date	Apr. 1, 2045	Apr. 1, 2045

Long-Term Debt (Schedule Of Lon

Long-Term Debt (Schedule Of Long-Term Debt) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Unamortized discount and debt issuance costs	$ (34)	$ (36)
Less amount due currently	(324)	(324)
Long-term debt, less amounts due currently	5,517	5,515
5.000% Fixed Senior Notes Due September 30, 2017 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 324	$ 324
Interest percentage	5.00%	5.00%
Due date	Sep. 30, 2017	Sep. 30, 2017
6.800% Fixed Senior Notes Due September 1, 2018 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 550	$ 550
Interest percentage	6.80%	6.80%
Due date	Sep. 1, 2018	Sep. 1, 2018
2.150% Fixed Senior Notes Due June 1, 2019 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 250	$ 250
Interest percentage	2.15%	2.15%
Due date	Jun. 1, 2019	Jun. 1, 2019
5.750% Fixed Senior Notes Due September 30, 2020 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 126	$ 126
Interest percentage	5.75%	5.75%
Due date	Sep. 30, 2020	Sep. 30, 2020
4.100% Fixed Senior Notes Due June 1, 2022 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 400	$ 400
Interest percentage	4.10%	4.10%
Due date	Jun. 1, 2022	Jun. 1, 2022
7.000% Fixed Debentures Due September 1, 2022 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 800	$ 800
Interest percentage	7.00%	7.00%
Due date	Sep. 1, 2022	Sep. 1, 2022
2.950% Fixed Senior Notes due April 1, 2025 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 350	$ 350
Interest percentage	2.95%	2.95%
Due date	Apr. 1, 2025	Apr. 1, 2025
7.000% Fixed Senior Notes Due May 1, 2032 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 500	$ 500
Interest percentage	7.00%	7.00%
Due date	May 1, 2032	May 1, 2032
7.250% Fixed Senior Notes Due January 15, 2033 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 350	$ 350
Interest percentage	7.25%	7.25%
Due date	Jan. 15, 2033	Jan. 15, 2033
7.500% Fixed Senior Notes Due September 1, 2038 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 300	$ 300
Interest percentage	7.50%	7.50%
Due date	Sep. 1, 2038	Sep. 1, 2038
5.250% Fixed Senior Notes Due September 30, 2040 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 475	$ 475
Interest percentage	5.25%	5.25%
Due date	Sep. 30, 2040	Sep. 30, 2040
4.550% Fixed Senior Notes Due December 1, 2041 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 400	$ 400
Interest percentage	4.55%	4.55%
Due date	Dec. 1, 2041	Dec. 1, 2041
5.300% Fixed Senior Notes Due June 1, 2042 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 500	$ 500
Interest percentage	5.30%	5.30%
Due date	Jun. 1, 2042	Jun. 1, 2042
3.750% Fixed Senior Notes due April 1, 2045 [Member]
Debt Instrument [Line Items]
Fixed Senior Note	$ 550	$ 550
Interest percentage	3.75%	3.75%
Due date	Apr. 1, 2045	Apr. 1, 2045
Bondco [Member]
Debt Instrument [Line Items]
Less amount due currently	$ (324)	$ (324)

Membership Interests (Narrative

Membership Interests (Narrative) (Details) - USD ($) $ in Millions	Apr. 27, 2017	Mar. 31, 2017	Mar. 31, 2017	Mar. 31, 2016
Subsequent Event [Line Items]
Assumed debt to equity ratio, debt			60.00%
Assumed debt to equity ratio, equity			40.00%
Cash available for distribution under the capital structure restriction		$ 89	$ 89
Regulatory capitalization ratio, debt			59.50%
Regulatory capitalization ratio, equity			40.50%
Cash distribution to members		$ 86	$ 86	$ 56
Subsequent Event [Member]
Subsequent Event [Line Items]
Cash distribution to members	$ 86

Membership Interests (Schedule

Membership Interests (Schedule Of Changes To Membership Interests) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2017	Mar. 31, 2016
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Balance		$ 7,711	$ 7,508
Net income		73	81
Distributions	$ (86)	(86)	(56)
Net effects of cash flow hedges (net of tax)		1
Balance	7,699	7,699	7,533
Capital Accounts [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Balance		7,822	7,621
Net income		73	81
Distributions		(86)	(56)
Net effects of cash flow hedges (net of tax)
Balance	7,809	7,809	7,646
Accumulated Other Comprehensive Income (Loss) [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Balance		(111)	(113)
Net income
Distributions
Net effects of cash flow hedges (net of tax)		1
Balance	$ (110)	$ (110)	$ (113)

Membership Interests (Schedul35

Membership Interests (Schedule Of Changes To Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	$ (111)
Balance at end of period	(110)
Cash Flow Hedges - Interest Rate Swap [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(20)	$ (22)
Defined benefit pension plans (net of tax)
Amounts reclassified from accumulated other comprehensive income (loss) and reported in interest expense and related charges	1
Balance at end of period	(19)	(22)
Defined Benefit Pension and OPEB Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(91)	(91)
Defined benefit pension plans (net of tax)
Amounts reclassified from accumulated other comprehensive income (loss) and reported in interest expense and related charges
Balance at end of period	(91)	(91)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(111)	(113)
Defined benefit pension plans (net of tax)
Amounts reclassified from accumulated other comprehensive income (loss) and reported in interest expense and related charges	1
Balance at end of period	$ (110)	$ (113)

Pension And OPEB Plans (Narrati

Pension And OPEB Plans (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Regulatory assets	$ 1,959	$ 1,974
Oncor Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.04%
Expected return on plan assets	5.17%
Vistra Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.28%
Expected return on plan assets	5.13%
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash contributions	$ 1
Additional cash contributions	148
Additional cash contributions, next five years	$ 586
OPEB Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.35%
Expected return on plan assets	6.10%
Cash contributions	$ 8
Additional cash contributions	23
Additional cash contributions, next five years	$ 153

Pension And OPEB Plans (Schedul

Pension And OPEB Plans (Schedule Of Pension And OPEB Plan Costs) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Net costs	$ 36	$ 34
Components of net OPEB costs:
Total benefit costs	36	34
Less amounts recognized principally as property or a regulatory asset	(25)	(25)
Net amounts recognized as expense	11	9
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	6	6
Interest cost	33	34
Expected return on assets	(29)	(31)
Amortization of net loss	11	10
Net costs	21	19
Components of net OPEB costs:
Total benefit costs	21	19
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2
Interest cost	12	12
Expected return on assets	(2)	(2)
Amortization of prior service cost	(5)	(5)
Amortization of net loss	8	8
Net costs	15	15
Components of net OPEB costs:
Total benefit costs	$ 15	$ 15

Related-Party Transactions (Nar

Related-Party Transactions (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Related Party Transaction [Line Items]
Revenues from electricity delivery fees		$ 220
TCEH [Member]
Related Party Transaction [Line Items]
Revenues from electricity delivery fees		220
EFH Corp [Member]
Related Party Transaction [Line Items]
Administrative and services costs		1
Shared facilities expense		1
Cash receipts from members related to federal income taxes	$ 135
Texas Transmission Investment LLC [Member]
Related Party Transaction [Line Items]
Cash receipts from members related to federal income taxes	$ 15
Sponsor Group [Member]
Related Party Transaction [Line Items]
Equity in existing vendor	16.60%
Cash payments to vendors	$ 45
Trade payables related parties	9
Sponsor Group [Member] | Capitalized [Member]
Related Party Transaction [Line Items]
Cash payments to vendors	42
Sponsor Group [Member] | Operation And Maintenance Expense [Member]
Related Party Transaction [Line Items]
Cash payments to vendors	$ 3
Maximum [Member] | EFH Corp [Member]
Related Party Transaction [Line Items]
Shared facilities payments received		$ 1

Related-Party Transactions (Sch

Related-Party Transactions (Schedule Of Related Party Transactions) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Federal income taxes receivable	$ (6)	$ (80)
Texas margin taxes payable	25	20
Net payable (receivable)	19	(60)
EFH Corp [Member]
Related Party Transaction [Line Items]
Federal income taxes receivable	(1)	(62)
Texas margin taxes payable	25	20
Net payable (receivable)	24	(42)
Texas Transmission Investment LLC [Member]
Related Party Transaction [Line Items]
Federal income taxes receivable	(5)	(18)
Net payable (receivable)	$ (5)	$ (18)

Supplementary Financial Infor40

Supplementary Financial Information (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Supplemental Financial Information [Line Items]
Aggregate amortization expenses	$ 15	$ 16
Goodwill	$ 4,064		$ 4,064
Sales [Member] | Vistra [Member]
Supplemental Financial Information [Line Items]
Concentration risk percentage	23.00%	23.00%
Sales [Member] | Nonaffiliated REP [Member]
Supplemental Financial Information [Line Items]
Concentration risk percentage	18.00%	16.00%
Trade Accounts Receivable [Member] | Vistra [Member]
Supplemental Financial Information [Line Items]
Concentration risk percentage	14.00%		15.00%
Trade Accounts Receivable [Member] | Nonaffiliated REP [Member]
Supplemental Financial Information [Line Items]
Concentration risk percentage	11.00%		12.00%

Supplementary Financial Infor41

Supplementary Financial Information (Schedule Of Other Income And (Deductions)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Supplementary Financial Information [Abstract]
Professional fees	$ (5)	$ (4)
Non-recoverable pension and OPEB (Note 9)	(1)	(1)
Other	2
Total other income and (deductions) - net	$ (4)	$ (5)

Supplementary Financial Infor42

Supplementary Financial Information (Schedule Of Interest Expense And Related Charges) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Supplementary Financial Information [Abstract]
Interest	$ 86	$ 85
Amortization of debt issuance costs and discounts	1	1
Less allowance for funds used during construction — capitalized interest portion	(2)	(2)
Total interest expense and related charges	$ 85	$ 84

Supplementary Financial Infor43

Supplementary Financial Information (Schedule Of Trade Accounts And Other Receivables) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Supplementary Financial Information [Abstract]
Gross trade accounts and other receivables	$ 508	$ 548
Allowance for uncollectible accounts	(3)	(3)
Trade accounts receivable - net	$ 505	$ 545

Supplementary Financial Infor44

Supplementary Financial Information (Summary of Investments And Other Property) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Supplementary Financial Information [Abstract]
Assets related to employee benefit plans, including employee savings programs	$ 101	$ 98
Land and other investments	2	2
Total investments and other property	$ 103	$ 100

Supplementary Financial Infor45

Supplementary Financial Information (Schedule Of Property, Plant And Equipment) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Supplementary Financial Information [Abstract]
Total assets in service	$ 20,385	$ 20,234
Less accumulated depreciation	6,935	6,836
Net of accumulated depreciation	13,450	13,398
Construction work in progress	649	416
Held for future use	15	15
Property, plant and equipment - net	$ 14,114	$ 13,829

Supplementary Financial Infor46

Supplementary Financial Information (Schedule Of Intangible Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 970	$ 961
Accumulated Amortization	435	420
Net	535	541
Land Easements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	494	491
Accumulated Amortization	96	94
Net	398	397
Capitalized Software [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	476	470
Accumulated Amortization	339	326
Net	$ 137	$ 144

Supplementary Financial Infor47

Supplementary Financial Information (Schedule Of Estimated Aggregate Amortization Expenses) (Details) $ in Millions	Mar. 31, 2017USD ($)
Supplementary Financial Information [Abstract]
2,017	$ 57
2,018	51
2,019	48
2,020	47
2,021	$ 47

Supplementary Financial Infor48

Supplementary Financial Information (Schedule Of Employee Benefit Obligations And Other) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Supplementary Financial Information [Abstract]
Retirement plans and other employee benefits	$ 2,091	$ 2,092
Uncertain tax positions (including accrued interest)	3	3
Investment tax credits	12	12
Other	70	61
Total employee benefit obligations and other	$ 2,176	$ 2,168

Supplementary Financial Infor49

Supplementary Financial Information (Schedule Of Supplemental Cash Flow Information) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Supplementary Financial Information [Abstract]
Interest		$ 99	$ 98
Less capitalized interest		(2)	(2)
Interest payments (net of amounts capitalized)		97	96
Federal		(150)
Noncash construction expenditures	[1]	$ 133	$ 82
[1]	Represents end-of-period accruals.