Related Party Transactions	12 Months Ended
Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Each project entered into O&M and administrative services agreements (ASAs) with subsidiaries of NEER whereby the projects pay a certain annual fee plus actual costs incurred in connection with certain O&M and administrative services performed under these agreements. These services are reflected as operations and maintenance in NEP's consolidated statements of income. Additionally, a NEP subsidiary pays an affiliate for transmission services which are reflected as operations and maintenance in NEP's consolidated statements of income. Certain projects have also entered into various types of agreements including those related to shared facilities and transmission lines, transmission line easements, technical support and construction coordination with subsidiaries of NEER whereby certain fees or cost reimbursements are paid to, or received by, certain subsidiaries of NEER. Management Services Agreement (MSA) - Under the MSA, an indirect wholly owned subsidiary of NEE provides operational, management and administrative services to NEP, including managing NEP’s day-to-day affairs and providing individuals to act as NEP’s executive officers and directors, in addition to those services that are provided under the existing O&M agreements and ASAs described above between NEER subsidiaries and NEP subsidiaries. NEP OpCo pays NEE an annual management fee equal to the greater of 1% of the sum of NEP OpCo’s net income plus interest expense, income tax expense and depreciation and amortization expense less certain non-cash, non-recurring items for the most recently ended fiscal year and $4 million (as adjusted for inflation beginning in 2016), which is paid in quarterly installments with an additional payment each January to the extent 1% of the sum of NEP OpCo’s net income plus interest expense, income tax expense and depreciation and amortization expense less certain non-cash, non-recurring items for the preceding fiscal year exceeds $4 million (as adjusted for inflation beginning in 2016). NEP OpCo also makes certain payments to NEE based on the achievement by NEP OpCo of certain target quarterly distribution levels to its common unitholders. NEP’s O&M expenses for the years ended December 31, 2017, 2016 and 2015 include approximately $67 million, $42 million and $6 million, respectively, related to the MSA. Cash Sweep and Credit Support Agreement (CSCS agreement) - NEP OpCo is a party to a CSCS agreement with NEER, under which NEER and certain of its subsidiaries provide credit support in the form of letters of credit and guarantees to satisfy NEP’s subsidiaries’ contractual obligations. NEP OpCo will pay NEER an annual credit support fee based on the level and cost of the credit support provided, payable in quarterly installments. NEP’s O&M expenses for the years ended December 31, 2017, 2016 and 2015 include approximately $4 million, $3 million and less than $2 million, respectively, related to the CSCS agreement. NEER and certain of its subsidiaries may withdraw funds (Project Sweeps) received by NEP OpCo under the CSCS agreement, or its subsidiaries in connection with certain long-term debt agreements, and hold those funds in accounts belonging to NEER or its subsidiaries to the extent the funds are not required to pay project costs or otherwise required to be maintained by NEP's subsidiaries. NEER and its subsidiaries may keep the funds until the financing agreements permit distributions to be made, or, in the case of NEP OpCo, until such funds are required to make distributions or to pay expenses or other operating costs or NEP OpCo otherwise demands the return of such funds. If NEER fails to return withdrawn funds when required by NEP's subsidiaries’ financing agreements, the lenders will be entitled to draw on any credit support provided by NEER in the amount of such withdrawn funds. If NEER or one of its affiliates realizes any earnings on the withdrawn funds prior to the return of such funds, it will be permitted to retain those earnings. At December 31, 2017 and 2016, the cash sweep amounts held in accounts belonging to NEER or its subsidiaries were approximately $87 million and $65 million, respectively, and are included in due from related parties on NEP’s consolidated balance sheets. Guarantees and Letters of Credit Entered into by Related Parties - Certain PPAs include requirements of the project entities to meet certain performance obligations. NextEra Energy Capital Holdings, Inc. (NEECH) or NEER has provided letters of credit or guarantees for certain of these performance obligations and payment of any obligations from the transactions contemplated by the PPAs. In addition, certain financing agreements require cash and cash equivalents to be reserved for various purposes. In accordance with the terms of these financing agreements, guarantees from NEECH have been substituted in place of these cash and cash equivalents reserve requirements. Also, under certain financing agreements, indemnifications have been provided by NEECH. In addition, certain interconnection agreements and site certificates require letters of credit or a bond to secure certain payment or restoration obligations related to those agreements. NEECH also guarantees the Project Sweep amounts held in accounts belonging to NEER as described above. At December 31, 2017, NEECH or NEER guaranteed or provided indemnifications, letters of credit or bonds totaling approximately $626 million related to these obligations. Agreements related to the sale of differential membership interests require NEER to guarantee payments due by the VIEs and the indemnifications to the VIEs' respective investors. At December 31, 2017, NEER guaranteed a total of approximately $119 million related to these obligations. Due to Related Party - Non-current amounts due to related party on NEP's consolidated balance sheets primarily represent amounts owed by certain of NEP's wind projects to NEER to refund NEER for certain transmission costs paid on behalf of the wind projects. Amounts will be paid to NEER as the wind projects receive payments from third parties for related notes receivable recorded in other non-current assets on NEP’s consolidated balance sheets. Development, Engineering and Construction Commitments - During the year ended December 31, 2015, NEER purchased and contributed approximately $24 million under several engineering, procurement and construction contracts related to the procurement of materials and services for certain NEP assets which were acquired while under construction and for which costs were capitalized in construction work in progress. There were no such purchases or contributions in the years ended December 31, 2017 and 2016. Transportation and Fuel Management Agreements - In connection with the acquisition of the Texas pipeline business described in Note 3, a subsidiary of NEP assigned to a subsidiary of NEER certain gas commodity agreements in exchange for entering into transportation agreements and a fuel management agreement whereby the benefits of the gas commodity agreements (net of transportation paid to the NEP subsidiary) are passed back to the NEP subsidiary. During the years ended December 31, 2017 and 2016, NEP recognized approximately $9 million and $12 million respectively, in revenues related to the transportation and fuel management agreements.

Related Party Transactions

Each project entered into O&M and administrative services agreements (ASAs) with subsidiaries of NEER whereby the projects pay a certain annual fee plus actual costs incurred in connection with certain O&M and administrative services performed under these agreements. These services are reflected as operations and maintenance in NEP's consolidated statements of income. Additionally, a NEP subsidiary pays an affiliate for transmission services which are reflected as operations and maintenance in NEP's consolidated statements of income. Certain projects have also entered into various types of agreements including those related to shared facilities and transmission lines, transmission line easements, technical support and construction coordination with subsidiaries of NEER whereby certain fees or cost reimbursements are paid to, or received by, certain subsidiaries of NEER.

Management Services Agreement (MSA) - Under the MSA, an indirect wholly owned subsidiary of NEE provides operational, management and administrative services to NEP, including managing NEP’s day-to-day affairs and providing individuals to act as NEP’s executive officers and directors, in addition to those services that are provided under the existing O&M agreements and ASAs described above between NEER subsidiaries and NEP subsidiaries. NEP OpCo pays NEE an annual management fee equal to the greater of 1% of the sum of NEP OpCo’s net income plus interest expense, income tax expense and depreciation and amortization expense less certain non-cash, non-recurring items for the most recently ended fiscal year and $4 million (as adjusted for inflation beginning in 2016), which is paid in quarterly installments with an additional payment each January to the extent 1% of the sum of NEP OpCo’s net income plus interest expense, income tax expense and depreciation and amortization expense less certain non-cash, non-recurring items for the preceding fiscal year exceeds $4 million (as adjusted for inflation beginning in 2016). NEP OpCo also makes certain payments to NEE based on the achievement by NEP OpCo of certain target quarterly distribution levels to its common unitholders. NEP’s O&M expenses for the years ended December 31, 2017, 2016 and 2015 include approximately $67 million, $42 million and $6 million, respectively, related to the MSA.

Cash Sweep and Credit Support Agreement (CSCS agreement) - NEP OpCo is a party to a CSCS agreement with NEER, under which NEER and certain of its subsidiaries provide credit support in the form of letters of credit and guarantees to satisfy NEP’s subsidiaries’ contractual obligations. NEP OpCo will pay NEER an annual credit support fee based on the level and cost of the credit support provided, payable in quarterly installments. NEP’s O&M expenses for the years ended December 31, 2017, 2016 and 2015 include approximately $4 million, $3 million and less than $2 million, respectively, related to the CSCS agreement.

NEER and certain of its subsidiaries may withdraw funds (Project Sweeps) received by NEP OpCo under the CSCS agreement, or its subsidiaries in connection with certain long-term debt agreements, and hold those funds in accounts belonging to NEER or its subsidiaries to the extent the funds are not required to pay project costs or otherwise required to be maintained by NEP's subsidiaries. NEER and its subsidiaries may keep the funds until the financing agreements permit distributions to be made, or, in the case of NEP OpCo, until such funds are required to make distributions or to pay expenses or other operating costs or NEP OpCo otherwise demands the return of such funds. If NEER fails to return withdrawn funds when required by NEP's subsidiaries’ financing agreements, the lenders will be entitled to draw on any credit support provided by NEER in the amount of such withdrawn funds. If NEER or one of its affiliates realizes any earnings on the withdrawn funds prior to the return of such funds, it will be permitted to retain those earnings. At December 31, 2017 and 2016, the cash sweep amounts held in accounts belonging to NEER or its subsidiaries were approximately $87 million and $65 million, respectively, and are included in due from related parties on NEP’s consolidated balance sheets.

Guarantees and Letters of Credit Entered into by Related Parties - Certain PPAs include requirements of the project entities to meet certain performance obligations. NextEra Energy Capital Holdings, Inc. (NEECH) or NEER has provided letters of credit or guarantees for certain of these performance obligations and payment of any obligations from the transactions contemplated by the PPAs. In addition, certain financing agreements require cash and cash equivalents to be reserved for various purposes. In accordance with the terms of these financing agreements, guarantees from NEECH have been substituted in place of these cash and cash equivalents reserve requirements. Also, under certain financing agreements, indemnifications have been provided by NEECH. In addition, certain interconnection agreements and site certificates require letters of credit or a bond to secure certain payment or restoration obligations related to those agreements. NEECH also guarantees the Project Sweep amounts held in accounts belonging to NEER as described above. At December 31, 2017, NEECH or NEER guaranteed or provided indemnifications, letters of credit or bonds totaling approximately $626 million related to these obligations. Agreements related to the sale of differential membership interests require NEER to guarantee payments due by the VIEs and the indemnifications to the VIEs' respective investors. At December 31, 2017, NEER guaranteed a total of approximately $119 million related to these obligations.

Due to Related Party - Non-current amounts due to related party on NEP's consolidated balance sheets primarily represent amounts owed by certain of NEP's wind projects to NEER to refund NEER for certain transmission costs paid on behalf of the wind projects. Amounts will be paid to NEER as the wind projects receive payments from third parties for related notes receivable recorded in other non-current assets on NEP’s consolidated balance sheets.

Development, Engineering and Construction Commitments - During the year ended December 31, 2015, NEER purchased and contributed approximately $24 million under several engineering, procurement and construction contracts related to the procurement of materials and services for certain NEP assets which were acquired while under construction and for which costs were capitalized in construction work in progress. There were no such purchases or contributions in the years ended December 31, 2017 and 2016.

Transportation and Fuel Management Agreements - In connection with the acquisition of the Texas pipeline business described in Note 3, a subsidiary of NEP assigned to a subsidiary of NEER certain gas commodity agreements in exchange for entering into transportation agreements and a fuel management agreement whereby the benefits of the gas commodity agreements (net of transportation paid to the NEP subsidiary) are passed back to the NEP subsidiary. During the years ended December 31, 2017 and 2016, NEP recognized approximately $9 million and $12 million respectively, in revenues related to the transportation and fuel management agreements.