Acquisitions, Investments and Dispositions	9 Months Ended
Sep. 30, 2016
Equity Method Investments and Joint Ventures [Abstract]
Acquisitions, Investments and Dispositions	Acquisitions, Investments and Dispositions Acquisitions and Investments Texas Solar 7 In January 2016, Con Edison Development acquired a 100 percent interest in a company that is the owner of a 106 MW (AC) solar electric production project in Texas (Texas Solar 7) for $227 million; $218 million was recorded as non-utility construction work in progress and the remaining $9 million was recorded as other receivables. At September 30, 2016 net assets of the project are approximately $123 million. The project has been financed, in part, by debt secured by the project (see Note C). Electricity generated by this project is to be purchased by the City of San Antonio pursuant to a long-term power purchase agreement. The project commenced commercial operation in the third quarter of 2016. Con Edison's interest in Texas Solar 7 is consolidated in the financial statements. Mountain Valley Pipeline In January 2016, CET Gas acquired a 12.5 percent equity interest in Mountain Valley Pipeline, LLC (MVP), a company developing a proposed gas transmission project in West Virginia and Virginia. The company's initial contribution to MVP was $18 million. At September 30, 2016, CET Gas' investment in MVP was $41 million. The estimated total project cost is $3,000 million to $3,500 million. Subject to FERC approval, MVP is targeting to be fully in-service during 2018. Con Edison is accounting for its equity interest in MVP as an equity method investment. Stagecoach Gas Services In April 2016, a CET Gas subsidiary agreed with a subsidiary of Crestwood to form a joint venture to own, operate and further develop existing natural gas pipeline and storage businesses located in northern Pennsylvania and southern New York. The transaction was substantially completed during June 2016. Crestwood contributed businesses to a new entity, Stagecoach, and the CET Gas subsidiary purchased a 50 percent equity interest in Stagecoach for $945 million (subject to closing adjustments). At September 30, 2016, CET Gas' investment in Stagecoach was $968 million. Con Edison is accounting for its equity interest in Stagecoach as an equity method investment. NY Transco In January 2016, CECONY entered into an agreement to transfer certain electric transmission projects to NY Transco, a company in which CET Electric has a 45.7 percent equity interest. In April 2016, the NYSPSC authorized CECONY, subject to certain conditions, to transfer the projects to NY Transco. In May 2016, CECONY transferred the projects to NY Transco for a purchase price of $122 million and an $8 million payment for easement rights on certain associated property. At September 30, 2016, CET Electric's investment in NY Transco was $53 million. Con Edison is accounting for its equity interest in NY Transco as an equity method investment. Pilesgrove In June 2016, Con Edison Development recorded an $8 million ($5 million, net of taxes) impairment charge on its 50 percent interest in Pilesgrove Solar, LLC (Pilesgrove), which owns an 18 MW (AC) solar electric production project in New Jersey. In August 2016, Con Edison Development acquired the remaining 50 percent interest in Pilesgrove for a purchase price of approximately $16 million and recorded a bargain purchase gain of $8 million ($5 million, net of taxes). The impairment charge and bargain purchase gain are included in Investment and other income on Con Edison’s consolidated income statement. Con Edison's interest in Pilesgrove is consolidated in the financial statements subsequent to the August 2016 acquisition. At September 30, 2016, net assets of the project are approximately $48 million, consisting primarily of $45 million recorded as non-utility property and $3 million recorded in current assets. Panoche Valley In October 2016, Con Edison Development acquired the remaining 50 percent interest in Panoche Holdings, LLC, which is developing a 240 MW (AC) solar electric production project in California, for cash consideration of $37 million, net of applicable purchase price adjustments. Con Edison will consolidate the project on its financial statements as of the date of acquisition. See Note M. Dispositions Pike County Light & Power Company (Pike) In October 2015, upon evaluating strategic alternatives, O&R entered into an agreement to sell Pike to Corning Natural Gas Holding Corporation (Corning). In August 2016, the sale was completed. O&R received cash consideration of $15 million for the sale. O&R has agreed to provide transition services to Corning for operations and customer support for a period of up to 18 months subsequent to the sale. In addition, O&R will continue to purchase and sell to Pike electric and gas commodity for three years. Pike has an option to extend the service for up to an additional three years. At September 30, 2015, O&R recorded an impairment charge of $5 million ($3 million, net of taxes), representing the difference between the carrying amount of Pike’s assets and the estimated sales proceeds. At December 31, 2015, Pike’s total assets and liabilities held for sale were $23 million and $5 million, respectively. There were no amounts outstanding at September 30, 2016. Con Edison Solutions' Retail Electric Supply Business In July 2016, Con Edison Solutions entered into an agreement to sell the assets of its retail electric supply business (including retail contracts, related derivative instruments, information systems, and accounts receivable) to a subsidiary of Exelon Corporation (Exelon). In September 2016, the sale was completed for cash consideration of $235 million, subject to working capital adjustments. The sale resulted in a gain of $104 million ($47 million, net of taxes), inclusive of a $65 million ($42 million, net of taxes) gain on derivative instruments. The tax effect of the sale includes $29 million ($19 million, net of federal tax) of state taxes related to a change in the apportionment of state income taxes. Con Edison Solutions has agreed to provide transition services to the Exelon subsidiary for operations and customer support through the end of 2017 during which period certain guarantees or other credit support provided by Con Edison in connection with the retail electric supply business may continue in effect. See Note H. At December 31, 2015, Con Edison Solutions' total assets and liabilities held for sale were $134 million and $84 million, respectively. There were no amounts outstanding at September 30, 2016.

Acquisitions, Investments and Dispositions

Acquisitions and Investments

Texas Solar 7

In January 2016, Con Edison Development acquired a 100 percent interest in a company that is the owner of a 106 MW (AC) solar electric production project in Texas (Texas Solar 7) for $227 million; $218 million was recorded as non-utility construction work in progress and the remaining $9 million was recorded as other receivables. At September 30, 2016 net assets of the project are approximately $123 million. The project has been financed, in part, by debt secured by the project (see Note C). Electricity generated by this project is to be purchased by the City of San Antonio pursuant to a long-term power purchase agreement. The project commenced commercial operation in the third quarter of 2016. Con Edison's interest in Texas Solar 7 is consolidated in the financial statements.

Mountain Valley Pipeline

In January 2016, CET Gas acquired a 12.5 percent equity interest in Mountain Valley Pipeline, LLC (MVP), a company developing a proposed gas transmission project in West Virginia and Virginia. The company's initial contribution to MVP was $18 million. At September 30, 2016, CET Gas' investment in MVP was $41 million. The estimated total project cost is $3,000 million to $3,500 million. Subject to FERC approval, MVP is targeting to be fully in-service during 2018. Con Edison is accounting for its equity interest in MVP as an equity method investment.

Stagecoach Gas Services

In April 2016, a CET Gas subsidiary agreed with a subsidiary of Crestwood to form a joint venture to own, operate and further develop existing natural gas pipeline and storage businesses located in northern Pennsylvania and southern New York. The transaction was substantially completed during June 2016. Crestwood contributed businesses to a new entity, Stagecoach, and the CET Gas subsidiary purchased a 50 percent equity interest in Stagecoach for $945 million (subject to closing adjustments). At September 30, 2016, CET Gas' investment in Stagecoach was $968 million. Con Edison is accounting for its equity interest in Stagecoach as an equity method investment.

NY Transco

In January 2016, CECONY entered into an agreement to transfer certain electric transmission projects to NY Transco, a company in which CET Electric has a 45.7 percent equity interest. In April 2016, the NYSPSC authorized CECONY, subject to certain conditions, to transfer the projects to NY Transco. In May 2016, CECONY transferred the projects to NY Transco for a purchase price of $122 million and an $8 million payment for easement rights on certain associated property. At September 30, 2016, CET Electric's investment in NY Transco was $53 million. Con Edison is accounting for its equity interest in NY Transco as an equity method investment.

Pilesgrove

In June 2016, Con Edison Development recorded an $8 million ($5 million, net of taxes) impairment charge on its 50 percent interest in Pilesgrove Solar, LLC (Pilesgrove), which owns an 18 MW (AC) solar electric production project in New Jersey. In August 2016, Con Edison Development acquired the remaining 50 percent interest in Pilesgrove for a purchase price of approximately $16 million and recorded a bargain purchase gain of $8 million ($5 million, net of taxes). The impairment charge and bargain purchase gain are included in Investment and other income on Con Edison’s consolidated income statement. Con Edison's interest in Pilesgrove is consolidated in the financial statements subsequent to the August 2016 acquisition. At September 30, 2016, net assets of the project are approximately $48 million, consisting primarily of $45 million recorded as non-utility property and $3 million recorded in current assets.

Panoche Valley

In October 2016, Con Edison Development acquired the remaining 50 percent interest in Panoche Holdings, LLC, which is developing a 240 MW (AC) solar electric production project in California, for cash consideration of $37 million, net of applicable purchase price adjustments. Con Edison will consolidate the project on its financial statements as of the date of acquisition. See Note M.

Dispositions

Pike County Light & Power Company (Pike)

In October 2015, upon evaluating strategic alternatives, O&R entered into an agreement to sell Pike to Corning Natural Gas Holding Corporation (Corning). In August 2016, the sale was completed. O&R received cash consideration of $15 million for the sale. O&R has agreed to provide transition services to Corning for operations and customer support for a period of up to 18 months subsequent to the sale. In addition, O&R will continue to purchase and sell to Pike electric and gas commodity for three years. Pike has an option to extend the service for up to an additional three years.

At September 30, 2015, O&R recorded an impairment charge of $5 million ($3 million, net of taxes), representing the difference between the carrying amount of Pike’s assets and the estimated sales proceeds. At December 31, 2015, Pike’s total assets and liabilities held for sale were $23 million and $5 million, respectively. There were no amounts outstanding at September 30, 2016.

Con Edison Solutions' Retail Electric Supply Business

In July 2016, Con Edison Solutions entered into an agreement to sell the assets of its retail electric supply business (including retail contracts, related derivative instruments, information systems, and accounts receivable) to a subsidiary of Exelon Corporation (Exelon). In September 2016, the sale was completed for cash consideration of $235 million, subject to working capital adjustments. The sale resulted in a gain of $104 million ($47 million, net of taxes), inclusive of a $65 million ($42 million, net of taxes) gain on derivative instruments. The tax effect of the sale includes $29 million ($19 million, net of federal tax) of state taxes related to a change in the apportionment of state income taxes. Con Edison Solutions has agreed to provide transition services to the Exelon subsidiary for operations and customer support through the end of 2017 during which period certain guarantees or other credit support provided by Con Edison in connection with the retail electric supply business may continue in effect. See Note H. At December 31, 2015, Con Edison Solutions' total assets and liabilities held for sale were $134 million and $84 million, respectively. There were no amounts outstanding at September 30, 2016.