Commitments and Contingencies Disclosure [Abstract] Long-term Purchase Commitment [Table Text Block] Long-term Purchase Commitment [Table Text Block] Future minimum lease commitments under operating leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Earnings (Loss) Per Share Disclosure [Abstract] -- None. No documentation exists for this element. -- Earnings Per Share Earnings Per Share [Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] NRG Yield, Inc - BS [Abstract] NRG Yield, Inc - BS [Abstract] Statement [Table] Statement [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] NRG Yield, Inc. NRG Yield, Inc. [Member] NRG Yield, Inc. [Member] NRG Yield [Member] NRG Yield [Member] NRG Yield [Member] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common Class A [Member] Common Class A [Member] Common Stock [Member] Common Stock [Member] Common Class B [Member] Common Class B [Member] Statement Statement [Line Items] Deferred income taxes Deferred Tax Assets, Net, Current Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Investments in subsidiaries Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Deferred Finance Costs, Noncurrent, Net Deferred Finance Costs, Noncurrent, Net Notes Receivable, Related Parties Notes Receivable, Related Parties Deferred Tax Assets, Gross Deferred Tax Assets, Net, Noncurrent Total Assets Assets Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Long-term Debt Long-term Debt Total Liabilities Liabilities Preferred stock, $0.01 par value; 10,000,000 shares authorized; none issued Preferred Stock, Value, Issued Common Stock, Value, Issued Common Stock, Value, Issued Additional Paid in Capital Additional Paid in Capital Retained Earnings (Accumulated Deficit) Retained Earnings (Accumulated Deficit) Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated Other Comprehensive Income (Loss), Net of Tax Noncontrolling interest Stockholders' Equity Attributable to Noncontrolling Interest Total Stockholders' Equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total Liabilities and Stockholders’ Equity Liabilities and Equity Common Stock, Par or Stated Value Per Share Common Stock, Par or Stated Value Per Share Preferred Stock, Par or Stated Value Per Share Preferred Stock, Par or Stated Value Per Share Preferred Stock, Shares Authorized Preferred Stock, Shares Authorized Preferred Stock, Shares Issued Preferred Stock, Shares Issued Common Stock, Shares Authorized Common Stock, Shares Authorized Common Stock, Shares, Issued Common Stock, Shares, Issued Statement of Comprehensive Income [Abstract] Unrealized gain/loss on derivatives, income tax expense /(benefit) Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Equity Method Investments and Joint Ventures [Abstract] Investments Accounted for by the Equity Method and Variable Interest Entities Equity Method Investments and Joint Ventures Disclosure [Text Block] Property, Plant and Equipment [Abstract] Schedule of Property, Plant and Equipment Property, Plant and Equipment [Table Text Block] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] CVSR CVSR [Member] CVSR [Member] GCE Holdings LLC GCE Holding LLC [Member] Represents the GCE Holding LLC GCE Holding LLC which wholly-owns GenConn Energy LLC. Schedule of Equity Method Investments Schedule of Equity Method Investments [Line Items] Summarized financial information of equity method investment Equity Method Investments [Table Text Block] Debt Disclosure [Abstract] Long-term Debt Long-term Debt [Text Block] Fair Value Disclosures [Abstract] Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Customer [Axis] Customer [Axis] Customer [Domain] Customer [Domain] Southern California Edison [Member] Southern California Edison [Member] Southern California Edison [Member] PG&E [Member] PG&E [Member] PG&E [Member] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Affiliated Entity [Member] Affiliated Entity [Member] Business Segments [Axis] Segments [Axis] Segment [Domain] Segments [Domain] Conventional Generation Conventional Generation [Member] Conventional Generation [Member] Renewables Renewables [Member] Renewables [Member] Thermal Thermal [Member] Represents Thermal segment of the entity. Corporate Corporate Segment [Member] Segment Reporting Segment Reporting Information [Line Items] Customer's Percentage of Total Revenue Customer's Percentage of Total Revenue Customer's Percentage of Total Revenue Total operating revenues Revenues Cost of operations Operating Expenses Depreciation and amortization Depreciation, Depletion and Amortization General and administrative — affiliate General and Administrative Expense Business Combination, Acquisition Related Costs Business Combination, Acquisition Related Costs Operating income Operating Income (Loss) Equity in earnings of unconsolidated affiliates Income (Loss) from Equity Method Investments Other Nonoperating Income (Expense) Other Nonoperating Income (Expense) Interest Expense Interest Expense Income Before Income Taxes Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Income tax expense Income Tax Expense (Benefit) Net Income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Equity investments in affiliates Equity Method Investments Capital Expenditures Capital Expenditures Represents amount of total Capital expenditures including accruals pertaining to repowering of entity's projects, major maintenance and meeting environmental commitments. Total Assets Related Party Transactions [Abstract] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] El Segundo [Member] El Segundo [Member] El Segundo [Member] CVSR [Member] Thermal [Member] NRG Yield, Inc. [Member] NRG Renew LLC [Member] NRG Renew LLC [Member] NRG Renew LLC [Member] GCE Holding LLC [Member] Marsh Landing [Member] Marsh Landing [Member] Marsh Landing [Member] Power Generation Facilities by Type [Axis] Power Generation Facilities by Type [Axis] The types of power generation facilities included in the entity's total global generation portfolio. Power Generation Facilities, Type [Domain] Power Generation Facilities, Type [Domain] Listing of power generation facilities included in the entity's total global generation portfolio. Utility-Scale Solar [Member] Utility-Scale Solar [Member] Utility-Scale Solar [Member] NRG [Member] NRG [Member] NRG [Member] NRG Repowering Holdings LLC [Member] NRG Repowering Holdings LLC [Member] NRG Repowering Holdings LLC [Member] Plan Scenario, Plan [Member] Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] NRG El Segundo Operations, Inc. [Member] NRG El Segundo Operations, Inc. [Member] NRG El Segundo Operations, Inc. [Member] NRG Construction Services LLC [Member] NRG Construction Services LLC [Member] NRG Construction Services LLC [Member] NRG El Segundo Operations, Inc. [Member] El Segundo Power, LLC [Member] El Segundo Power, LLC [Member] Management Services Agreement with NRG Management Services Agreement with NRG [Member] Management Services Agreement with NRG [Member] NRG Power Marketing LLC [Member] NRG Power Marketing LLC [Member] NRG Power Marketing LLC [Member] GenOn Energy Services LLC [Member] GenOn Energy Services LLC [Member] GenOn Energy Services LLC [Member] Related Party Transaction Related Party Transaction [Line Items] Management Services Fee, Annual Service Management Costs Management Services Fee, Increase Service Management Costs, Fee Increase Service Management Costs, Fee Increase Due to Related Parties Due to Related Parties Interest Due to Related Parties Interest Due to Related Parties Interest Due to Related Parties Capital contributions percentage Capital contributions percentage Capital contributions percentage Due to Affiliate Due to Affiliate Related Party Transaction, Expenses from Transactions with Related Party Related Party Transaction, Expenses from Transactions with Related Party Related Party Costs, Capitalized Amount Related Party Costs, Capitalized Amount Related Party Costs, Capitalized Amount Payments Payments Payments Receipt of payments Receipt of payments Receipt of payments coal, gas purchases coal, gas purchases coal, gas purchases Cost of Natural Gas Purchases Cost of Natural Gas Purchases Equity Method Investment, Ownership Percentage Equity Method Investment, Ownership Percentage Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring [Member] Fair Value, Measurements, Recurring [Member] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Reported Value Measurement [Member] Reported Value Measurement [Member] Estimate of Fair Value Measurement [Member] Estimate of Fair Value Measurement [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Derivatives, Fair Value, by Derivative Instrument Risk [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest rate contracts Interest Rate Contract [Member] Commodity contracts Commodity Contract [Member] Fair Value of Financial Instruments Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Derivative Asset, Fair Value Determined Using Valuation Techniques, Percentage Derivative Asset, Fair Value Determined Using Valuation Techniques, Percentage This element represents the portion of total fair value of all derivative assets, which are valued using various valuation techniques including internal models based on a fundamental analysis of the market and extrapolation of observable market data with similar characteristics. Fair Value Assets, Measured on Recurring Basis, Valuation Techniques, Impact of Credit Reserve to Fair Value Fair Value Assets, Measured on Recurring Basis, Valuation Techniques, Impact of Credit Reserve to Fair Value This element represents the increase (decrease) to fair value from applying a credit reserve to reflect credit risk on the valuation techniques used to measure fair value of Level 2 and 3 derivative contracts which is calculated based on credit default swaps. Derivative Assets Derivative Asset, Fair Value, Gross Asset Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value Financing Receivable, Net Financing Receivable, Net Notes receivable — affiliate Notes Receivable, Related Parties, Noncurrent Notes receivable, including current portion Financing Receivable, Gross Long-term debt, including current portion Derivative Assets (Liabilities), at Fair Value, Net Derivative Assets (Liabilities), at Fair Value, Net Derivative Liabilities Derivative Liability, Fair Value, Gross Liability Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset and Liability, Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases Concentration of Credit Risk Concentration of Credit Risk [Abstract] Concentration of Credit Risk [Abstract] Credit risk exposure under certain long-term agreements for the next five years Concentration Risk, Credit Risk, Financial Instrument, Maximum Exposure Period of credit risk exposure under certain long-term agreements (in years) Estimated Counterparty Credit Risk Exposure to Certain Counterparties, Period Estimated Counterparty Credit Risk Exposure to Certain Counterparties, Period Fair Value, Assets, Level 1 to Level 2 Transfers, Amount Fair Value, Assets, Level 1 to Level 2 Transfers, Amount Nature of Business Disclosure [Abstract] -- None. No documentation exists for this element. -- IPO of NRG Yield IPO of NRG Yield [Table Text Block] [Table Text Block] for IPO of NRG Yield [Table] The Company's operating assets are comprised of the following projects: Schedule of Ownership Percentage, Net Capacity, Offtake Counterparty and Year of Offtake Expiration by Operating Asset [Table Text Block] Schedule of Ownership Percentage, Net Capacity, Offtake Counterparty and Year of Offtake Expiration by Operating Asset [Table Text Block] Schedule of Effective Interest Rate [Table Text Block] Schedule of Effective Interest Rate [Table Text Block] Schedule of Effective Interest Rate [Table Text Block] Schedule of long-term debt Schedule of Debt [Table Text Block] Summary of swaps related to the Company's project level debt Schedule of Derivative Instruments [Table Text Block] Schedule of annual payments based on the maturities of NRG Yield's debt Schedule of Maturities of Long-term Debt [Table Text Block] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Common Class C [Member] Common Class C [Member] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Basic and diluted earnings per share attributable to NRG Yield, Inc. Class A common stockholders Earnings Per Share Attributable To Reporting Entity Shareholders Basic [Abstract] Numerator: Net Income (Loss) Available to Common Stockholders, Basic [Abstract] Net income attributable to NRG Yield, Inc. Net Income (Loss) Available to Common Stockholders, Basic Denominator: Weighted Average Number of Shares Outstanding, Basic [Abstract] Weighted average number of common shares outstanding Weighted Average Number of Shares Outstanding, Basic and Diluted Basic and diluted loss per share: Earnings Per Share, Basic [Abstract] Earnings per weighted average common share — basic and diluted Earnings Per Share, Basic and Diluted Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Statement of Financial Position [Abstract] Drop-down Acquisition [Member] Drop-down Acquisition [Member] Drop-down Acquisition [Member] EME-NYLD Assets [Member] EME-NYLD Assets [Member] EME-NYLD Assets [Member] Equity in Earnings of Consolidated Subsidiaries Equity in Earnings of Consolidated Subsidiaries This item represents the proportionate share of the parent in the earnings of the consolidated subsidiaries. Less: Net income attributable to NRG (b) Net Income (Loss) Attributable to Noncontrolling Interest Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Quarterly Financial Information Disclosure [Abstract] Summary of Unaudited Quarterly Financial Data Schedule of Quarterly Financial Information [Table Text Block] Schedule of Segment Reporting Information, by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Segment Reporting Segment Reporting Disclosure [Text Block] Environmental Remediation Obligations [Abstract] Environmental Loss Contingency Disclosure [Text Block] Environmental Loss Contingency Disclosure [Text Block] Predecessor Predecessor [Member] Other Comprehensive (Loss) Income, net of tax Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Unrealized (loss) gain on derivatives, net of income tax benefit (expense) of $5, $(16), and $7 Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Other comprehensive (loss) income Other Comprehensive Income (Loss), Net of Tax Comprehensive Income (Loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive income attributable to noncontrolling interest Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive Income (Loss), Net of Tax, Available for Common Stockholders Comprehensive Income (Loss), Net of Tax, Attributable to Parent Nature of Business Business Description and Basis of Presentation [Text Block] Income Statement [Abstract] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Noncontrolling Interest Noncontrolling Interest [Member] Operating Revenues Revenues [Abstract] Operating Costs and Expenses Operating Costs and Expenses [Abstract] Cost of operations Cost of Revenue Acquisition-related transaction and integration costs Business Combination, Integration Related Costs Total operating costs and expenses Costs and Expenses Operating Income Other Income (Expense) Costs and Expenses [Abstract] Equity in earnings of unconsolidated affiliates Other income, net Interest expense Total other expense Nonoperating Income (Expense) Net Income excluding pre-acquisition net income of Acquired ROFO assets Net Income excluding pre-acquisition net income of Acquired ROFO assets Net Income excluding pre-acquisition net income of Acquired ROFO assets Earnings Per Share Attributable to NRG Yield, Inc. Class A and Class C Common Stockholders: Earnings Per Share [Abstract] Dividends Per Class A Common Share Common Stock, Dividends, Per Share, Cash Paid Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Schedule of Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Borrego Borrego [Member] Borrego [Member] TA - High Desert LLC [Member] TA - High Desert LLC [Member] TA - High Desert LLC [Member] Kansas South [Member] Kansas South [Member] Kansas South [Member] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Support Equipment and Facilities [Member] Support Equipment and Facilities [Member] Land and improvements Land and Land Improvements [Member] Property, Plant and Equipment Property, Plant and Equipment [Line Items] Renewable energy grant, gross Renewable energy grant, gross Renewable energy grant, gross Deferred Tax Assets, Deferred Income Deferred Tax Assets, Deferred Income Property, plant and equipment, gross Property, Plant and Equipment, Gross Under construction Construction in Progress, Gross Less accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property, Plant and Equipment, Net Property, Plant and Equipment, Net Property, plant and equipment, useful life Property, Plant and Equipment, Useful Life Renewable energy grants, net Renewable energy grants, net Renewable energy grants, net Deferred tax asset, renewable energy grant Deferred tax asset, renewable energy grant Deferred tax asset, renewable energy grant Proceeds from renewable energy grants Proceeds from Renewable Energy Grants The amount of cash received during the period for renewable energy grants related to capital projects. Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Accounting for Derivative Instruments and Hedging Activities Disclosure [Abstract] -- None. No documentation exists for this element. -- Derivative [Table] Derivative [Table] Successor Successor [Member] Measurement Unit [Axis] Measurement Unit [Axis] Represents information pertaining to various measurement units. Measurement Unit [Domain] Measurement Unit [Domain] Represents various measurement units used by the entity. MMbtu MMbtu [Member] Represents unit of measurement that is used to measure quantity of natural gas. Dollars United States of America, Dollars Derivatives by Underlying Assets [Axis] Derivatives by Underlying Assets [Axis] Derivatives by the underlying asset from which its value is derived. Underlying Assets [Domain] Underlying Assets [Domain] Major types of referenced/ underlying assets. Natural Gas [Member] Natural Gas [Member] Interest Interest [Member] Details pertaining to interest rate swaps which are considered a derivative commodity. Interest rate contracts current Interest Rate Contract Current [Member] The current portion of a derivative instrument whose primary underlying risk is tied to the right to receive or pay a sum of money at a given interest rate. Interest rate contracts long-term Interest Rate Contract Non Current [Member] The noncurrent portion of a derivative instrument whose primary underlying risk is tied to the right to receive or pay a sum of money at a given interest rate. Commodity contracts current Commodity Contract Current [Member] The current portion of a derivative instrument whose primary underlying risk is tied to commodity prices. Hedging Designation [Axis] Hedging Designation [Domain] Derivatives Designated as Cash Flow Hedges Designated as Hedging Instrument [Member] Derivatives Not Designated as Cash Flow Hedges Not Designated as Hedging Instrument [Member] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Member] Derivative Derivative [Line Items] Derivative Liability Derivative Liability Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3 Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Underlying, Derivative Underlying, Derivative Derivative, Notional Amount Derivative, Notional Amount Fair Value of Derivative Instruments Derivative, Fair Value, Net [Abstract] Derivative Liabilities Derivative instruments Derivative Asset Fair Value of Gross Derivative Assets/(Liabilities), Net Fair Value of Gross Derivative Assets/(Liabilities), Net Fair value of gross derivative assets less fair value of gross derivative liabilities. Derivative Liability, Fair Value, Gross Asset Derivative Liability, Fair Value, Gross Asset Derivative Asset, Fair Value, Gross Liability Derivative Asset, Fair Value, Gross Liability Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset Derivative Asset, Fair Value, Amount Offset Against Collateral Net Of Derivative Liability, Fair Value, Amount Offset Against Collateral Derivative Asset, Fair Value, Amount Offset Against Collateral Net Of Derivative Liability, Fair Value, Amount Offset Against Collateral Derivative Asset, Fair Value, Amount Offset Against Collateral Net Of Derivative Liability, Fair Value, Amount Offset Against Collateral Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Accumulated OCL beginning balance Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax Mark-to-market of cash flow hedge accounting contracts Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Accumulated OCL ending balance, net of income tax benefit of $6, $1 and $17, respectively Accumulated OCL ending balance, net of income tax benefit of $6, $1 and $17, respectively Accumulated Other Comprehensive Income (Loss), Cumulative Change in Gain (Loss) from Cash Flow Hedges, Tax Amount Accumulated Other Comprehensive Income (Loss), Cumulative Change in Gain (Loss) from Cash Flow Hedges, Tax Amount Loss expected to be realized from OCI during the next 12 months, net of tax Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Summary of Derivative Instruments Impact on Results of Operations Summary of Derivative Instruments Impact on Results of Operations [Abstract] Unrealized gain/(loss) on derivatives Unrealized Gain (Loss) on Derivatives Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3 Fair Value, Assets, Level 2 to Level 1 Transfers, Amount Fair Value, Assets, Level 2 to Level 1 Transfers, Amount Fair Value, Liabilities, Level 1 to Level 2 Transfers, Amount Fair Value, Liabilities, Level 1 to Level 2 Transfers, Amount Fair Value, Liabilities, Level 2 to Level 1 Transfers, Amount Fair Value, Liabilities, Level 2 to Level 1 Transfers, Amount Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months, Tax Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months, Tax The estimated tax impact of existing gains or losses on cash flow hedges, at the reporting date, which are expected to be reclassified to earnings within the next 12 months. Derivative, Collateral, Right to Reclaim Cash Derivative, Collateral, Right to Reclaim Cash Derivative, Collateral, Obligation to Return Cash Derivative, Collateral, Obligation to Return Cash Accounting for Derivative Instruments and Hedging Activities Derivative Instruments and Hedging Activities Disclosure [Text Block] Document And Entity Information [Abstract] -- None. No documentation exists for this element. -- Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Class of Stock Class of Stock [Line Items] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date Entity Current Reporting Status Entity Current Reporting Status Entity Filer Category Entity Filer Category Entity Voluntary Filers Entity Voluntary Filers Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] CVSR Financing Agreement CVSR Financing Agreement [Member] CVSR Financing Agreement [Member] Avenal Avenal [Member] Avenal [Member] High Plains Ranch II High Plains II [Member] High Plains II [Member] GenConn Energy LLC Gen Conn Energy LLC [Member] Represents the information pertaining to GenConn Energy LLC. NRG Eurus Energy EurusEnergy [Member] EurusEnergy [Member] Lender Name [Axis] Lender Name [Axis] Line of Credit Facility, Lender [Domain] Line of Credit Facility, Lender [Domain] Syndicate of Banks SyndicateofBanks [Member] SyndicateofBanks [Member] Power Generation Facilities [Axis] Power Generation Facilities [Axis] The power generation facilities included in the entity's total global generation portfolio. Power Generation Facilities [Domain] Power Generation Facilities [Domain] Power Generation Facilities [Domain] GenConn Devon GenConn Devon [Member] GenConn Devon [Member] GenConn Middletown GenConn Middletown [Member] GenConn Middletown [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Fixed Rate Notes Fixed Rate Notes [Member] Fixed Rate Notes [Member] Working Capital Facility [Member] Working Capital Facility [Member] Working Capital Facility [Member] Variable Interest Entity Variable Interest Entity [Line Items] Economic interest in equity method investments (as a percent) Power Generation Capacity (in MWs) Power Generation Capacity, Megawatts The generation capacity of the entity's power generation facilities as of the balance sheet date, expressed in megawatts. Power Purchase Agreement Period Power Purchase Agreement Period Represents the period of power purchase agreement Notes and Loans Payable Notes and Loans Payable Interest rate Debt Instrument, Interest Rate, Stated Percentage Operating revenues Current assets Assets, Current Non-current assets Assets, Noncurrent Current liabilities Liabilities, Current Non-current liabilities Liabilities, Noncurrent Power Generation Units, Number Power Generation Units, Number The number of power generation units as of the balance sheet date. Number of Units Reached Commercial Operation at Peaking Generation Facilities Number of Units Reached Commercial Operation at Peaking Generation Facilities This element represents the number of units reached commercial operation at the peaking generation facilities during the period. Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Maximum Borrowing Capacity Retained Earnings, Undistributed Earnings from Equity Method Investees Retained Earnings, Undistributed Earnings from Equity Method Investees Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Other Borrowings Other Borrowings Stockholders' Equity Attributable to Parent [Abstract] Schedule of Distributions Paid [Table Text Block] Schedule of Distributions Paid [Table Text Block] Schedule of Distributions Paid [Table Text Block] Schedule of Dividends Paid [Table Text Block] Schedule of Dividends Paid [Table Text Block] Tabular disclosure of all or some of the information related to dividends paid Reconciliation of NRG's basic earnings per share to diluted earnings per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Statement of Cash Flows [Abstract] Operating Income (Loss) Income (Loss) from Equity Method Investments Net Cash Provided by (Used in) Operating Activities Net Cash Provided by (Used in) Operating Activities Payments of Capital Distribution Payments of Capital Distribution Proceeds from Issuance of Long-term Debt Proceeds from Issuance of Long-term Debt Increase (Decrease) in Notes Receivable, Related Parties Increase (Decrease) in Notes Receivable, Related Parties Net Cash Used in Investing Activities Net Cash Provided by (Used in) Investing Activities Proceeds from issuance of Class A common stock Proceeds from Issuance of Common Stock Payments of Financing Costs Payments of Financing Costs Proceeds from Contributions from Affiliates Proceeds from Contributions from Affiliates Payments of Ordinary Dividends, Common Stock Payments of Ordinary Dividends, Common Stock Net Cash Provided by Financing Activities Net Cash Provided by (Used in) Financing Activities Cash and Cash Equivalents, Period Increase (Decrease) Cash and Cash Equivalents, Period Increase (Decrease) Nature of Business [Table] Nature of Business [Table] Nature of Business [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] NRG Yield LLC NRG Yield LLC [Member] NRG Yield LLC [Member] GenConn Devon [Member] Marsh Landing Walnut Creek [Member] Walnut Creek [Member] Walnut Creek [Member] Alpine Alpine [Member] Alpine [Member] Avra Valley Avra Valley [Member] Avra Valley [Member] NRG Solar Blythe LLC [Member] NRG Solar Blythe LLC [Member] Represents NRG Solar Blythe LLC, a wholly-owned subsidiary of the entity. Roadrunner NRG Solar Roadrunner LLC [Member] NRG Solar Roadrunner LLC [Member] RE Kansas South [Member] RE Kansas South [Member] RE Kansas South [Member] AZ DG Solar Projects AZ DG Solar Projects [Member] AZ DG Solar Projects [Member] PFMG DG Solar Projects PFMG DG Solar Projects [Member] PFMG DG Solar Projects [Member] Alta I [Member] Alta I [Member] Alta I [Member] Alta II [Member] Alta II [Member] alta II [Member] Alta III [Member] Alta III [Member] Alta III Alta IV [Member] Alta IV [Member] Alta IV [Member] Alta V [Member] Alta V [Member] Alta V [Member] Alta X [Member] Alta X [Member] Alta X [Member] Alta XI [Member] Alta XI [Member] Alta XI [Member] South Trent South Trent Holding LLC [Member] South Trent Holding LLC [Member] Laredo Ridge [Member] Laredo Ridge [Member] Laredo Ridge [Member] Taloga [Member] Taloga [Member] Taloga [Member] Pinnacle [Member] Pinnacle [Member] Pinnacle [Member] Buffalo Bear [Member] Buffalo Bear [Member] Buffalo Bear [Member] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Class A Common Stockholders [Member] Class A Common Stockholders [Member] Class A Common Stockholders [Member] Public Shareholders [Member] Public Shareholders [Member] Public Shareholders [Member] Conventional Utility-Scale Solar Distributed Solar Distributed Solar [Member] Distributed solar generation capacity. Wind Wind Farms [Member] Wind farm generation capacity. Nature of Business Basis of Presentation [Line Items] Basis of Presentation [Line Items] Megawatts Thermal Equivalent, Available Under right-to-use Provisions Megawatts Thermal Equivalent, Available Under right-to-use Provisions Megawatts Thermal Equivalent, Available Under right-to-use Provisions Sale of Stock, Number of Shares Issued in Transaction Sale of Stock, Number of Shares Issued in Transaction Payments to Acquire Interest in Subsidiaries and Affiliates Payments to Acquire Interest in Subsidiaries and Affiliates Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest Proceeds from Issuance Initial Public Offering Proceeds from Issuance Initial Public Offering Percentage of Ownership Percentage of Ownership Percentage of Ownership Allocation of Corporate Expenses Allocation of Corporate Expenses Allocation of Corporate Expenses Steam and Chilled Water Capacity, Megawatts Thermal Equivalent Steam and Chilled Water Capacity, Megawatts Thermal Equivalent The generation capacity of the entity's thermal power generation facilities as of the balance sheet date, expressed in megawatts thermal equivalent. Economic Interest in Entity Economic Interest in Entity Economic Interest in Entity Business Acquisitions, Consideration Transferred, Purchase Price Business Combination, Consideration Transferred Common Stock, Voting Rights Common Stock, Voting Rights Business Acquisitions, Consideration Transferred, Purchase Price Business Acquisitions, Consideration Transferred, Purchase Price Business Acquisitions, Consideration Transferred, Purchase Price Estimated carrying values and fair values of the Company's recorded financial instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Reconciliation of beginning and ending balances for financial instruments that are recognized at fair value in the consolidated financial statements at least annually using significant unobservable inputs Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Litigation Settlement, Amount Litigation Settlement, Amount Company's deferred tax assets and liabilities Components of Deferred Tax Assets and Liabilities [Abstract] Deferred tax liabilities: Deferred Tax Liabilities, Gross [Abstract] Deferred Tax Assets, Derivative Instruments Deferred Tax Assets, Derivative Instruments Deferred tax assets: Deferred Tax Assets, Gross [Abstract] Deferred Tax Assets, Other Deferred Tax Assets, Other U.S. Federal net operating loss carryforwards Deferred Tax Assets, Operating Loss Carryforwards, Domestic State net operating loss carryforwards Deferred Tax Assets, Operating Loss Carryforwards, State and Local Total deferred tax assets Deferred Tax Assets, Gross The Company's net deferred tax position Deferred Tax Assets, Net, Classification [Abstract] Net deferred tax asset — current Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Deferred Tax Assets, Net Deferred Tax Assets, Net Operating Loss Carryforwards [Table] Operating Loss Carryforwards [Table] Deferred Asset Type [Axis] Deferred Asset Type [Axis] Deferred Asset Type [Axis] Deferred Asset Type [Domain] Deferred Asset Type [Domain] [Domain] for Deferred Asset Type [Axis] Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] Domestic Tax Authority Domestic Tax Authority [Member] State and Local Jurisdiction State and Local Jurisdiction [Member] Operating Loss Carryforwards Operating Loss Carryforwards [Line Items] Operating Loss Carryforwards Operating Loss Carryforwards Common Class D [Member] Common Class D [Member] Common Class D [Member] ASSETS Assets [Abstract] Current Assets Assets, Current [Abstract] Restricted cash Restricted Cash and Cash Equivalents, Current Accounts receivable — trade Accounts Receivable, Net, Current Accounts receivable — affiliate Due from Affiliate, Current Inventory Inventory, Net Notes receivable Notes, Loans and Financing Receivable, Net, Current Renewable energy grant receivable Grants Receivable, Current Prepayments and other current assets Prepaid Expense and Other Assets, Current Total current assets Property, plant and equipment In service Property, Plant and Equipment, Other, Gross Total property, plant and equipment Net property, plant and equipment Other Assets Assets, Noncurrent [Abstract] Notes receivable Notes, Loans and Financing Receivable, Net, Noncurrent Intangible assets, net of accumulated amortization of $36 and $7 Finite-Lived Intangible Assets, Net Derivative instruments Derivative Instruments and Hedges, Noncurrent Deferred income taxes Other non-current assets Other Assets, Noncurrent Total other assets Other Assets LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities and Equity [Abstract] Current Liabilities Liabilities, Current [Abstract] Current portion of long-term debt Long-term Debt and Capital Lease Obligations, Current Accounts payable Accounts Payable, Current Accounts payable — affiliate Due to Affiliate, Current Derivative instruments Derivative Liability, Current Accrued expenses and other current liabilities Accrued Expenses and Other Current Liabilities Sum of accrued expenses and other current liabilities. Accrued expenses are the carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, that are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Other current liabilities are the aggregate carrying amount, as of the balance sheet date, of current liabilities not separately disclosed in the balance sheet due to materiality considerations. Current liabilities are expected to be paid within one year (or the normal operating cycle, if longer). Total current liabilities Total current liabilities Liabilities, Noncurrent [Abstract] Long-term debt Long-term Debt and Capital Lease Obligations Derivative instruments Derivative Liability, Noncurrent Other non-current liabilities Other Liabilities, Noncurrent Total non-current liabilities Commitments and Contingencies Commitments and Contingencies Stockholders' Equity Statement of Stockholders' Equity [Abstract] Schedule of Capitalization, Equity [Table] Schedule of Capitalization, Equity [Table] Acquired ROFO Assets [Domain] Acquired ROFO Assets [Domain] Acquired ROFO Assets [Domain] Scenario, Previously Reported [Member] Scenario, Previously Reported [Member] Cash [Member] Cash [Member] Non-cash [Member] Non-cash [Member] Non-cash [Member] Preferred Stock [Member] Preferred Stock [Member] Additional Paid-in Capital Additional Paid-in Capital [Member] Other Additional Capital [Member] Other Additional Capital [Member] Retained Earnings Retained Earnings [Member] Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) [Member] Statement of Stockholders' Equity Schedule of Capitalization, Equity [Line Items] Assets Transferred, Carrying Value Assets Transferred, Carrying Value Assets Transferred, Carrying Value Allocation of Predecessor's equity Allocation of Predecessor's equity Allocation of Predecessor's equity Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Unrealized gain/(loss) on derivatives Net Assets Acquired, ROFO Assets Net Assets Acquired, ROFO Assets Net Assets Acquired, ROFO Assets Partners' Capital Account, Contributions Partners' Capital Account, Contributions Proceeds from Contributions from Affiliates Partners' Capital Account, Return of Capital Partners' Capital Account, Return of Capital Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Common Stock, Value, Issued Stock Issued During Period, Value, New Issues Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt Non-cash addition to additional paid-in capital for change in tax basis of property, plant and equipment for assets acquired from NRG Adjustments to Additional Paid in Capital, Other Income Tax Contingency [Table] Income Tax Contingency [Table] Income Tax Disclosure Income Tax Contingency [Line Items] Unrecognized Tax Benefits Unrecognized Tax Benefits Deferred Tax Assets, Net Income Tax Expense (Benefit), Continuing Operations [Abstract] Income Tax Expense (Benefit), Continuing Operations [Abstract] Current Current Income Tax Expense (Benefit), Continuing Operations [Abstract] U.S. Federal Current Federal Tax Expense (Benefit) Total — current Current Income Tax Expense (Benefit) Deferred Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] U.S. Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Total — deferred Deferred Income Tax Expense (Benefit) Income tax expense Effective tax rate (as a percent) Effective Income Tax Rate Reconciliation, Percent Income Taxes Receivable Income Taxes Receivable U.S. federal statutory rate (as a percent) Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Reconciliation of the U.S. federal statutory rate to the Company's effective rate from continuing operations Effective Income Tax Rate Reconciliation, Percent [Abstract] Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Tax at 35% Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount State taxes, net of federal benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Impact of non-taxable equity earnings Income Tax Reconciliation, Impact of Non-taxible Equity Earning Income Tax Reconciliation, Impact of Non-taxible Equity Earning Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Amount Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Amount Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount Unaudited Quarterly Financial Data Quarterly Financial Information [Text Block] Net notional volume buy/(sell) of NRG Yield's open derivative transactions broken out by commodity Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Fair value within the derivative instrument valuation on the balance sheets Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location [Table Text Block] Offsetting of derivatives by counterparty master agreement level and collateral received or paid Offsetting Liabilities [Table Text Block] Effects of NRG Yield's accumulated OCI balance attributable to interest rate swaps designated as cash flow hedge derivatives, net of tax Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block] Summary of the components of the Company's intangible assets subject to amortization Schedule of Finite-Lived Intangible Assets [Table Text Block] Schedule of estimated amortization of NRG's intangible assets for each of the next five years Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument Period [Axis] Debt Instrument Period [Axis] Debt Instrument Period [Axis] Debt Instrument Period [Domain] Debt Instrument Period [Domain] [Domain] for Debt Instrument Period [Axis] October 8, 2013 to July 17, 2014 [Member] October 8, 2013 to July 17, 2014 [Member] October 8, 2013 to July 17, 2014 [Member] July 17, 2014 to December 31, 2017 [Member] July 17, 2014 to December 31, 2017 [Member] July 17, 2014 to December 31, 2017 [Member] January 1, 2018 to December 31, 2020 [Member] January 1, 2018 to December 31, 2020 [Member] January 1, 2018 to December 31, 2020 [Member] January 1, 2021 and thereafter [Member] January 1, 2021 and thereafter [Member] January 1, 2021 and thereafter [Member] September 26, 2014 to September 30, 2019 [Member] September 26, 2014 to September 30, 2019 [Member] September 26, 2014 to September 30, 2019 [Member] October 1, 2019 to September 30, 2031 [Member] October 1, 2019 to September 30, 2031 [Member] October 1, 2019 to September 30, 2031 [Member] December 17, 2014 to December 31, 2018 [Member] December 17, 2014 to December 31, 2018 [Member] December 17, 2014 to December 31, 2018 [Member] January 1, 2019 to December 31, 2023 [Member] January 1, 2019 to December 31, 2023 [Member] January 1, 2019 to December 31, 2023 [Member] January 1, 2024 to March 31, 2028 [Member] January 1, 2024 to March 31, 2028 [Member] January 1, 2024 to March 31, 2028 [Member] November 12, 2014 to December 20, 2018 [Member] November 12, 2014 to December 20, 2018 [Member] November 12, 2014 to December 20, 2018 [Member] December 21, 2018 to December 31, 2021 [Member] December 21, 2018 to December 31, 2021 [Member] December 21, 2018 to December 31, 2021 [Member] October 21, 2014 to September 30, 2018 [Member] October 21, 2014 to September 30, 2018 [Member] October 21, 2014 to September 30, 2018 [Member] October 1, 2018 to September 30, 2022 [Member] October 1, 2018 to September 30, 2022 [Member] October 1, 2018 to September 30, 2022 [Member] October 1, 2022 to May 31, 2023 [Member] October 1, 2022 to May 31, 2023 [Member] October 1, 2022 to May 31, 2023 [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR Floor [Member] LIBOR Floor [Member] LIBOR Floor [Member] Minimum [Member] Maximum [Member] Maturity Date [Axis] Maturity Date [Axis] Maturity Date [Axis] Maturity Date [Domain] Maturity Date [Domain] [Domain] for Maturity Date [Axis] December 31, 2015 [Member] December 31, 2015 [Member] December 31, 2015 [Member] December 30, 2034 [Member] December 30, 2034 [Member] December 30, 2034 [Member] January 31, 2031 [Member] January 31, 2031 [Member] January 31, 2031 [Member] May 15, 2031 [Member] May 15, 2031 [Member] May 15, 2031 [Member] March 31, 2020 [Member] March 31, 2020 [Member] March 31, 2020 [Member] June 30, 2035 [Member] June 30, 2035 [Member] June 30, 2035 [Member] December 31, 2025 [Member] December 31, 2025 [Member] December 31, 2025 [Member] December 31, 2020 [Member] December 31, 2020 [Member] December 31, 2020 [Member] Amount [Axis] Amount [Axis] Amount [Axis] Amount [Domain] Amount [Domain] [Domain] for Amount [Axis] 3.5% Convertible Notes due 2019 [Member] 3.5% Convertible Notes due 2019 [Member] 3.5% Convertible Notes due 2019 [Member] Alta Wind XI term loan after March 2018 [Member] Alta Wind XI term loan after March 2018 [Member] Alta Wind XI term loan after March 2018 [Member] Alta Wind X term loan after March 2018 [Member] Alta Wind X term loan after March 2018 [Member] Alta Wind X term loan after March 2018 [Member] Alta Wind I, lease financing arrangement, due 2034 [Member] Alta Wind I, lease financing arrangement, due 2034 [Member] Alta Wind I, lease financing arrangement, due 2034 [Member] Alta Realty Investments, due 2031 [Member] Alta Realty Investments, due 2031 [Member] Alta Realty Investments, due 2031 [Member] NRG Marsh Landing LLC, due 2017 and 2023 Marsh Landing Term Loan Facility [Member] Marsh Landing Term Loan Facility [Member] NRG Marsh Landing LLC, due 2023 Marsh Landing Tranche B due 2023 [Member] Marsh Landing Tranche B due 2023 [Member] Walnut Creek Energy, LLC, due in 2023 [Member] Walnut Creek Energy, LLC, due in 2023 [Member] Walnut Creek Energy, LLC, due in 2023 [Member] Tapestry Wind LLC due in 2021 [Member] Tapestry Wind LLC due in 2021 [Member] Tapestry Wind LLC due in 2021 [Member] Marsh Landing Tranche A due December 2017 [Member] Marsh Landing Tranche A due December 2017 [Member] Marsh Landing Tranche A due December 2017 [Member] Marsh Landing Term Loan Due 2023 [Member] Marsh Landing Term Loan Due 2023 [Member] Marsh Landing Term Loan Due 2023 [Member] NRG Solar Alpine LLC, due 2013 and 2022 Alpine Financing Agreement [Member] Alpine Financing Agreement [Member] NRG Solar Alpine, due 2022 Alpine Financing Agreement, due 2022 [Member] Alpine Financing Agreement, due 2022 [Member] Alpine [Member] NRG Energy Center Minneapolis LLC, senior secured notes, due 2013, 2017, and 2025 NRG Energy Center Minneapolis LLC Senior Secured Notes [Member] Represents senior secured notes financed by NRG Energy Center Minneapolis LLC, which are due 2013, 2017, and 2025. NRG Energy Center Minneapolis LLC, senior secured notes, due 2017 NRG Energy Center Minneapolis LLC Senior Secured Notes, due 2017 [Member] NRG Energy Center Minneapolis LLC Senior Secured Notes, due 2017 [Member] NRG Energy Center Minneapolis LLC, senior secured notes, due 2025 NRG Energy Center Minneapolis LLC Senior Secured Notes, due 2025 [Member] NRG Energy Center Minneapolis LLC Senior Secured Notes, due 2025 [Member] Laredo Ridge Wind, LLC, due in 2026 [Member] Laredo Ridge Wind, LLC, due in 2026 [Member] Laredo Ridge Wind, LLC, due in 2026 [Member] NRG Solar Borrego I LLC, due 2024 and 2038 Borrego Financing [Member] Borrego Financing [Member] NRG Borrego I LLC, due 2024 Borrego Financing Agreement, due 2024 [Member] Borrego Financing Agreement, due 2024 [Member] NRG Borrego I LLC, due 2038 Borrego Financing Agreement, due 2038 [Member] Borrego Financing Agreement, due 2038 [Member] South Trent Wind LLC, due 2020 South Trent Financing Agreement [Member] South Trent Financing Agreement [Member] NRG Solar Avra Valley LLC, due 2031 Avra Valley Financing Agreement [Member] Avra Valley Financing Agreement [Member] High Desert Facility [Member] High Desert Facility [Member] High Desert Facility [Member] WCEP Holdings, LLC, due in 2023 [Member] WCEP Holdings, LLC, due in 2023 [Member] WCEP Holdings, LLC, due in 2023 [Member] NRG Roadrunner LLC, due 2031 Roadrunner Financing Agreement [Member] Roundrunner Financing Agreement [Member] Kansas South Facility, due 2031 [Member] Kansas South Facility, due 2031 [Member] Kansas South Facility, due 2031 [Member] NRG Solar Blythe LLC, due 2028 NRG Solar Blythe LLC Credit Agreement Due 2028 [Member] Represent NRG Solar Blythe LLC credit agreement, which is due 2028. PFMG and related subsidiaries, due 2030 PFMG Financing Agreement [Member] PFMG Financing Agreement [Member] NRG Energy Center Princeton LLC, due 2017 NRG Energy Center Princeton LLC, due 2017 [Member] NRG Energy Center Princeton LLC, due 2017 [Member] South Trent Wind LLC South Trent Wind LLC [Member] Represents the information pertaining to South Trent Wind LLC. NRG Yield Revolving Credit Facility NRG Yield Revolving Credit Facility [Member] NRG Yield Revolving Credit Facility [Member] Convertible Debt [Member] Convertible Debt [Member] 5.375% Senior Notes due in 2024 [Member] 5.375% Senior Notes due in 2024 [Member] 5.375% Senior Notes due in 2024 [Member] Alta Wind Asset Management, due 2031 [Member] Alta Wind Asset Management, due 2031 [Member] Alta Wind Asset Management, due 2031 [Member] West Holdings Credit Agreement [Member] West Holdings Credit Agreement [Member] West Holdings Credit Agreement [Member] Alta Wind X, due 2020 [Member] Alta Wind X, due 2020 [Member] Alta Wind X, due 2020 [Member] Alta Wind XI, due 2020 [Member] Alta Wind XI, due 2020 [Member] Alta Wind XI, due 2020 [Member] Alta Wind I - V Lease financing arrangement [Member] Alta Wind I - V Lease financing arrangement [Member] Alta Wind I - V Lease financing arrangement [Member] Alta Wind II, lease financing arrangement, due 2034 [Member] Alta Wind II, lease financing arrangement, due 2034 [Member] Alta Wind II, lease financing arrangement, due 2034 [Member] Alta Wind III, lease financing arrangement, due 2034 [Member] Alta Wind III, lease financing arrangement, due 2034 [Member] Alta Wind III, lease financing arrangement, due 2034 [Member] Alta Wind IV, lease financing arrangement, due 2034 [Member] Alta Wind IV, lease financing arrangement, due 2034 [Member] Alta Wind IV, lease financing arrangement, due 2034 [Member] Alta Wind V, lease financing arrangement, due 2035 [Member] Alta Wind V, lease financing arrangement, due 2035 [Member] Alta Wind V, lease financing arrangement, due 2035 [Member] Project [Domain] Project [Domain] West Holdings Credit Agreement Tranche A [Member] West Holdings Credit Agreement Tranche A [Member] West Holdings Credit Agreement Tranche A [Member] West Holdings Credit Agreement Tranche B [Member] West Holdings Credit Agreement Tranche B [Member] West Holdings Credit Agreement Tranche B [Member] West Holdings PPA [Member] West Holdings PPA [Member] West Holdings PPA [Member] West Holding Collateral Agent [Member] West Holding Collateral Agent [Member] West Holding Collateral Agent [Member] West Holdings Working Capital Facility [Member] West Holdings Working Capital Facility [Member] West Holdings Working Capital Facility [Member] Kansas South Facility [Member] Kansas South Facility [Member] Kansas South Facility [Member] Avra Valley [Member] High Desert Facility, due 2033 [Member] High Desert Facility, due 2033 [Member] High Desert Facility, due 2033 [Member] TA - High Desert, due 2023 [Member] TA - High Desert, due 2023 [Member] TA - High Desert, due 2023 [Member] Tapestry Wind LLC due in 2029 [Member] Tapestry Wind LLC due in 2029 [Member] Tapestry Wind LLC due in 2029 [Member] Lease Financing Arrangement [Member] Lease Financing Arrangement [Member] Lease Financing Arrangement [Member] Revolving Credit Facility [Member] Revolving Credit Facility [Member] Letter of Support of Debt Service [Member] Letter of Support of Debt Service [Member] Letter of Support of Debt Service [Member] Notes Payable, Other Payables [Member] Notes Payable, Other Payables [Member] Letter of Credit Letter of Credit [Member] Cash Grant Loan Cash Grant Loan [Member] Cash Grant Loan [Member] Construction Loans Construction Loans [Member] Term Loan Facility Term Loan Facility [Member] Term Loan Facility [Member] Interest Rate Swap Maturity - June 30, 2023 Maturity - June 30, 2023 [Member] Maturity - June 30, 2023 [Member] Interest Rate Swap Maturity - June 14, 2020 Maturity - June14, 2020 [Member] Maturity - June14, 2020 [Member] Interest Rate Swap Maturity - June 14, 2028 Maturity - June 14, 2028 [Member] Maturity - June 14, 2028 [Member] Interest Rate Swap Maturity - December 31, 2029 Maturity - December 31, 2029 [Member] Maturity - December 31, 2029 [Member] Maturity - June 30, 2025 [Member] Maturity - June 30, 2025 [Member] Maturity - June 30, 2025 [Member] Interest Rate Swap Maturity - June 25, 2028 Maturity - June 25, 2028 [Member] Maturity - June 25, 2028 [Member] Interest Rate Swap Maturity - November 30, 2030 Maturity - November 30, 2030 [Member] Maturity - November 30, 2030 [Member] Floating Rate Notes [Member] Floating Rate Notes [Member] Floating Rate Notes [Member] Bridge Loan [Member] Bridge Loan [Member] NRG Wind LLC [Member] NRG Wind LLC [Member] NRG Wind LLC [Member] Alta Wind Asset Management [Member] Alta Wind Asset Management [Member] Alta Wind Asset Management [Member] NRG West Holdings LLC [Member] NRG West Holdings LLC [Member] NRG West Holdings LLC [Member] NRG Yield Operating LLC [Member] NRG Yield Operating LLC [Member] NRG Yield Operating LLC [Member] NRG Yield LLC [Member] NRG Solar Roadrunner LLC NRG Solar Blythe LLC NRG Solar Avra Valley LLC NRG Solar Avra Valley [Member] NRG Solar Avra Valley [Member] NRG Solar Alpine LLC NRG Solar Alpine LLC [Member] NRG Solar Alpine LLC [Member] Alta Realty Investments, LLC [Member] Alta Realty Investments, LLC [Member] Alta Realty Investments, LLC [Member] WCEP Holdings LLC [Member] WCEP Holdings LLC [Member] WCEP Holdings LLC [Member] EME [Member] EME [Member] EME [Member] Non-affiliated Entity [Member] Non-affiliated entity [Member] Non-affiliated entity [Member] Interest Rate Swaps Interest Rate Swap [Member] Forward Interest Rate Swap [Member] Forward Interest Rate Swap [Member] Forward Interest Rate Swap [Member] Current Interest Rate Swap [Member] Current Interest Rate Swap [Member] Current Interest Rate Swap [Member] Long-term Debt Disclosure Debt Instrument [Line Items] Interest Expense, Debt Interest Expense, Debt Convertible Debt, Fair Value Disclosures Conversion Value of Convertible Debt Conversion Value of Convertible Debt Debt Instrument, Interest Rate, Effective Percentage Debt Instrument, Interest Rate, Effective Percentage Long-term Debt Convertible Debt, Fair Value Disclosures Convertible Debt, Fair Value Disclosures Common Stock Closing Price Common Stock Closing Price Common Stock Closing Price Long-term debt, current maturities Long-term Debt, Current Maturities Long-term debt, excluding current maturities Long-term Debt, Excluding Current Maturities Variable rate basis Debt Instrument, Description of Variable Rate Basis Debt Instrument, Convertible, Carrying Amount of Equity Component Debt Instrument, Convertible, Carrying Amount of Equity Component Distribution Made to Limited Liability Company (LLC) Member, Cash Distributions Paid Distribution Made to Limited Liability Company (LLC) Member, Cash Distributions Paid Senior Notes Senior Notes Debt Instrument, Convertible, Conversion Price Debt Instrument, Convertible, Conversion Price Debt Instrument, Convertible, Conversion Ratio Debt Instrument, Convertible, Conversion Ratio Debt Instrument, Face Amount Debt Instrument, Face Amount Line of Credit Facility, Unused Capacity, Commitment Fee Percentage Line of Credit Facility, Unused Capacity, Commitment Fee Percentage Convertible Debt Convertible Debt Letters of Credit Outstanding, Amount Debt Instrument, Incremental Escalation On Basis Spread, Percentage Debt Instrument, Incremental Escalation On Basis Spread, Percentage Debt Instrument, Incremental Escalation on Basis Spread, Percentage Derivative, Minimum Percent of Outstanding Notional Amount Required to Have Fixed Interest Rate Percentage of Debt Hedged by Interest Rate Derivatives Derivative, Fixed Interest Rate Derivative, Fixed Interest Rate Notional Amount of Interest Rate Derivatives Proceeds from Contributions from Parent Proceeds from Contributions from Parent Line of Credit Facility, Increase, Additional Borrowings Proceeds from Lines of Credit Debt Issuance Cost Debt Issuance Cost Repayments of Debt Repayments of Debt Annual Payments Based on Maturities, 2015 Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months Annual Payments Based on Maturities, 2016 Long-term Debt, Maturities, Repayments of Principal in Year Two Annual Payments Based on Maturities, 2017 Long-term Debt, Maturities, Repayments of Principal in Year Three Annual Payments Based on Maturities, 2018 Long-term Debt, Maturities, Repayments of Principal in Year Four Annual Payments Based on Maturities, 2019 Long-term Debt, Maturities, Repayments of Principal in Year Five Annual Payments Based on Maturities, Thereafter Long-term Debt, Maturities, Repayments of Principal after Year Five Long-term Debt, Fair Value Long-term Debt, Fair Value Proceeds from Issuance of Senior Long-term Debt Proceeds from Issuance of Senior Long-term Debt Letters of Credit, Drawn Amount Letters of Credit, Drawn Amount Letters of Credit, Drawn Amount Letters of Credit, Issued Amount Letters of Credit, Issued Amount The total amount of the contingent obligation under letters of credit issued as of the reporting date. Line of Credit Facility, Fair Value of Amount Outstanding Line of Credit Facility, Fair Value of Amount Outstanding Extinguishment of Debt, Amount Extinguishment of Debt, Amount Line of Credit Facility, Maximum Borrowing Capacity Available for Issuance of Letters of Credit Line of Credit Facility, Maximum Borrowing Capacity Available for Issuance of Letters of Credit Line of Credit Facility, Maximum Borrowing Capacity Available for Issuance of Letters of Credit Debt Service Loan Commitment Debt Service Loan Commitment Debt Service Loan Commitment Line of Credit Facility, Commitment Fee Percentage Line of Credit Facility, Commitment Fee Percentage Amortization of Debt Discount (Premium) Amortization of Debt Discount (Premium) Amortization of Debt Issuance Costs Amortization of Debt Issuance Costs Amortization of Debt Issuance Costs Interest Expense at Effective Rate Interest Expense at Effective Rate Interest Expense at Effective Rate Proceeds from Issuance of Debt Proceeds from Issuance of Debt Credit Facility, Maximum Borrowing Capacity, Amendment Credit Facility, Maximum Borrowing Capacity, Amendment Credit Facility, Maximum Borrowing Capacity, Amendment Contingent Rental Income Associated with PPAs Operating Leases, Income Statement, Contingent Revenue Interest Costs Capitalized Interest Costs Capitalized Income Taxes, Threshold Percentage Income Taxes, Threshold Percentage The percentage that is likely to be realized upon settlement which is used as a basis of recording unrecognized tax benefits for income tax positions that have surpassed the more-likely-than-not threshold. Asset Retirement Obligation Asset Retirement Obligation Business Combinations [Abstract] Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Business Acquisition, Pro Forma Information [Table Text Block] Business Acquisition, Pro Forma Information [Table Text Block] Business Acquisition, Purchase Price [Table Text Block] Business Acquisition, Purchase Price [Table Text Block] Business Acquisition, Purchase Price [Table Text Block] Business Acquisition Mergers, Acquisitions and Dispositions Disclosures [Text Block] ROFO Assets [Member] ROFO Assets [Member] ROFO Assets [Member] Interest Paid, Net Interest Paid, Net Cash Flows from Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net income/(loss) Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Distributions and equity in earnings of unconsolidated affiliates Income (Loss) from Equity Method Investments, Net of Dividends or Distributions Depreciation and amortization Amortization of financing costs and debt discount/premiums Amortization of Financing Costs and Discounts Amortization of intangibles and out-of-market contracts Amortization of Intangibles and Out of Market Contracts The aggregate (income) expense recorded in earnings to allocate the cost of out-of-market contracts and intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash (income) expense, this element is added back to net income when calculating cash provided by (used in) operations using the indirect method. Changes in deferred income taxes Increase (Decrease) in Income Taxes Changes in derivative instruments Increase (Decrease) in Derivative Assets and Liabilities Changes in other working capital Increase (Decrease) in Other Operating Assets and Liabilities, Net Net Cash Provided by Operating Activities Cash Flows from Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Capital expenditures Payments to Acquire Property, Plant, and Equipment Acquisition of businesses, net of cash acquired Decrease (increase) in restricted cash Increase (Decrease) in Restricted Cash Decrease (increase) in notes receivable, including affiliates Increase (Decrease) in Notes Receivable The net change during the reporting period of amounts due from note holders for outstanding loans for both amounts due within one year (or one business cycle) and amounts due beyond one year. Proceeds from renewable energy grants Investments in unconsolidated affiliates (Investments in) Proceeds From Sales of Unconsolidated Affiliates (Investments in) Proceeds From Sales of Unconsolidated Affiliates Other Payments for (Proceeds from) Other Investing Activities Cash Flows from Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] Capital contributions from NRG Distributions and return of capital to NRG Payment of dividends and distributions Payments of Dividends Proceeds from issuance of long-term debt — external Payment of debt issuance costs Payments of Debt Issuance Costs Payments for long-term debt — external Proceeds from (Repayments of) Debt Payments for long-term debt — affiliate Proceeds from (Repayments of) Related Party Debt Net Increase (Decrease) in Cash and Cash Equivalents Cash and Cash Equivalents at Beginning of Period Cash and Cash Equivalents at End of Period Additions to fixed assets for accrued capital expenditures Capital Expenditures Incurred but Not yet Paid Decrease to fixed assets for accrued grants Decrease in Fixed Assets, Accrued Grants The decrease in fixed assets for accrued grants and related tax impact. Decrease to fixed assets for deferred tax asset Decrease in Fixed Assets, Deferred Tax Asset The decrease in fixed assets for deferred tax assets Dividend Declared [Member] Dividend Declared [Member] TA High Desert, RE Kansas South, and El Segundo Energy Center [Member] TA High Desert, RE Kansas South, and El Segundo Energy Center [Member] TA High Desert, RE Kansas South, and El Segundo Energy Center [Member] Expense Related to Distribution or Servicing and Underwriting Fees Expense Related to Distribution or Servicing and Underwriting Fees Common Stock, Dividends, Per Share, Declared Common Stock, Dividends, Per Share, Declared Business Combination, Separately Recognized Transactions, Net Gains and Losses Business Combination, Separately Recognized Transactions, Net Gains and Losses Payments of Capital Distribution Intangible assets, accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Income tax provision from continuing operations Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Reconciliation of the U.S. federal statutory rate to the Company's effective rate Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Company's deferred tax assets and liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Net Income (Loss) [Member] Net Income (Loss) [Member] Net Income (Loss) [Member] Operating Income (Loss) [Member] Operating Income (Loss) [Member] Operating Revenues [Member] Operating Revenues [Member] Operating Revenues [Member] Net Income/(Loss) per Weighted Average Common Share - Basic (in dollars per share) Earnings Per Share, Basic Weighted average number of common shares outstanding - basic (in shares) Weighted Average Number of Shares Outstanding, Basic Quarterly Financial Information, Quarterly Charges and Credits, Amount Reconciling to Previously Reported Results Quarterly Financial Information, Quarterly Charges and Credits, Amount Reconciling to Previously Reported Results Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Principles of Consolidation Consolidation, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Unrestricted Cash and Cash Equivalents, Policy [Policy Text Block] Restricted Cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Trade Receivables and Allowance for Doubtful Accounts Trade and Other Accounts Receivable, Policy [Policy Text Block] Inventory Inventory, Policy [Policy Text Block] Property, Plant and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Asset Impairments Impairment Or Disposal Of Long Lived Assets Policy And Equity Method Investments Policy [Text Block] Describes an entity's accounting policy for recognizing and measuring the impairment of long-lived assets and other-than temporary impairment of equity method investments. Capitalized Interest Interest Capitalization, Policy [Policy Text Block] Debt Issuance Costs Debt, Policy [Policy Text Block] Intangible Assets Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Revenue Recognition Revenue Recognition, Policy [Policy Text Block] Derivative Financial Instruments Derivatives, Policy [Policy Text Block] Concentrations of Credit Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Fair Value of Financial Instruments Fair Value of Financial Instruments, Policy [Policy Text Block] Asset Retirement Obligations Asset Retirement Obligations, Policy [Policy Text Block] Guarantees Guarantees, Indemnifications and Warranties Policies [Policy Text Block] Investments Accounted for by the Equity Method Equity Method Investments, Policy [Policy Text Block] Lease, Policy [Policy Text Block] Lease, Policy [Policy Text Block] Business Combinations Business Combinations Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Segment Reporting Segment Reporting, Policy [Policy Text Block] Recent Accounting Developments New Accounting Pronouncements, Policy [Policy Text Block] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Alta Wind Portfolio [Member] Alta Wind Portfolio [Member] Alta Wind Portfolio [Member] Alta Wind XI [Member] Alta Wind XI [Member] Alta Wind XI [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Customer Contracts Customer Contracts [Member] Customer Relationships Customer Relationships [Member] Supply Commitment Arrangement [Domain] Supply Commitment Arrangement [Domain] Other Intangible Assets [Member] Other Intangible Assets [Member] Emission Allowances [Member] Emission Allowances [Member] An asset acquired in a business combination representing an entity's emission allowances. Research and Development Expense [Member] Developed Technology Rights [Member] Leasehold Rights [Member] Leasehold Rights [Member] Leasehold Rights [Member] Out of Market Contracts [Member] Out of Market Contracts [Member] Out of Market Contracts [Member] Finite-Lived Intangible Assets Finite-Lived Intangible Assets [Line Items] Gross amount at the beginning of the period Finite-Lived Intangible Assets, Gross Acquisition of Alta Wind Portfolio Finite-lived Intangible Assets Acquired Gross amount at the end of the period Less accumulated amortization Net carrying amount Amortization of Intangible Assets Amortization of Intangible Assets Weighted average remaining amortization period (in years) Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Out of Market Contracts Out of Market Contracts Represents out-of-market contracts, which relate to customer contracts, energy supply contracts, power contracts, gas swaps, and certain coal contracts, where the contracted commodity price was less than the market price for revenue contracts and greater than market for cost contracts as of the acquisition date for contracts acquired in a business combination or the date of emergence from bankruptcy. The customer contracts, gas swaps and power contracts are amortized to revenues while the energy supply contracts and coal contracts are amortized to cost of operations over the term of the contracts. Finite-Lived Intangible Asset, Useful Life Finite-Lived Intangible Asset, Useful Life Finite-Lived Intangible Assets, Other Changes Finite-Lived Intangible Assets, Other Changes This element represents other additions or reductions to finite-lived intangible assets during the period. Contra Revenue Intangibles Amortization Contra Revenue Intangibles Amortization Intangibles Amortization recorded to contra-revenue account Accumulated Amortization of Out of Market Contracts Accumulated Amortization of Out of Market Contracts Accumulated Amortization of Out of Market Contracts Out of Market Contracts Amortization Expense Out of Market Contracts Amortization Expense Out of Market Contracts Amortization Expense Amortization Amortization Estimated amortization related to the Company's finite-lived intangible assets Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] Estimated intangible assets amortization, 2015 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months Estimated intangible assets amortization, 2016 Finite-Lived Intangible Assets, Amortization Expense, Year Two Estimated intangible assets amortization, 2017 Finite-Lived Intangible Assets, Amortization Expense, Year Three Estimated intangible assets amortization, 2018 Finite-Lived Intangible Assets, Amortization Expense, Year Four Estimated intangible assets amortization, 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Five Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block] Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block] Related Party Transactions Disclosure Related Party Transactions Disclosure [Text Block] Property, Plant and Equipment Disclosure Property, Plant and Equipment Disclosure [Text Block] Utilities Operating Expense, Purchased Power under Long-term Contracts Utilities Operating Expense, Purchased Power under Long-term Contracts Operating Leases, Rent Expense Operating Leases, Rent Expense Operating Leases, Future Minimum Payments Due, Next Twelve Months Operating Leases, Future Minimum Payments Due, Next Twelve Months Operating Leases, Future Minimum Payments, Due in Two Years Operating Leases, Future Minimum Payments, Due in Two Years Operating Leases, Future Minimum Payments, Due in Three Years Operating Leases, Future Minimum Payments, Due in Three Years Operating Leases, Future Minimum Payments, Due in Four Years Operating Leases, Future Minimum Payments, Due in Four Years Operating Leases, Future Minimum Payments, Due in Five Years Operating Leases, Future Minimum Payments, Due in Five Years Operating Leases, Future Minimum Payments, Due Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Operating Leases, Future Minimum Payments Due Operating Leases, Future Minimum Payments Due Purchase Obligation, Due in Next Twelve Months Purchase Obligation, Due in Next Twelve Months Unrecorded Unconditional Purchase Obligation, Due within Two Years Unrecorded Unconditional Purchase Obligation, Due within Two Years Unrecorded Unconditional Purchase Obligation, Due within Three Years Unrecorded Unconditional Purchase Obligation, Due within Three Years Unrecorded Unconditional Purchase Obligation, Due within Four Years Unrecorded Unconditional Purchase Obligation, Due within Four Years Unrecorded Unconditional Purchase Obligation, Due within Five Years Unrecorded Unconditional Purchase Obligation, Due within Five Years Unrecorded Unconditional Purchase Obligation, Due after Five Years Unrecorded Unconditional Purchase Obligation, Due after Five Years Purchase Obligation Purchase Obligation Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Tapestry Wind [Member] Tapestry Wind [Member] Tapestry Wind [Member] Alta Wind Holdings [Member] Alta Wind Holdings [Member] Alta Wind Holdings [Member] Energy Systems Energy Systems Company [Member] Energy Systems Company [Member] Marsh Landing Term Loan Facility Business Acquisition Business Acquisition [Line Items] Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets Business Acquisition, Pro Forma Revenue Business Acquisition, Pro Forma Revenue Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Cash Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Cash Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Cash Number of Facilities Number of Facilities Number of Facilities Payments to Acquire Businesses, Gross Payments to Acquire Businesses, Gross Business Combination, Integration Related Costs Business Combination, Consideration Transferred Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles Business Acquisition, Purchase Price Allocation, Intangible Assets, Other than Goodwill, Adjusted Business Acquisition, Purchase Price Allocation, Intangible Assets, Other than Goodwill, Adjusted Business Acquisition, Purchase Price Allocation, Intangible Assets, Other than Goodwill, Adjusted Working Capital Business Acquisition, Consideration Transferred, Working Capital Business Acquisition, Consideration Transferred, Working Capital Business Combination, Consideration Transferred, Liabilities Incurred Business Combination, Consideration Transferred, Liabilities Incurred Business Acquisition, Percentage of Voting Interests Acquired Business Acquisition, Percentage of Voting Interests Acquired Business Acquisition, Purchase Price Allocation, Assets Acquired (Liabilities Assumed), Net Adjusted Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment, Adjusted Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment, Adjusted Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment, Adjusted Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment, Adjusted Property, Plant, and Equipment, Fair Value Disclosure Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Noncurrent Liabilities Longterm Debt Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Noncurrent Liabilities Longterm Debt Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Noncurrent Liabilities Longterm Debt Business Acquisition, Purchase Price Allocation, Noncurrent Liabilities, Long-term Debt, Adjusted Business Acquisition, Purchase Price Allocation, Noncurrent Liabilities, Long-term Debt, Adjusted Business Acquisition, Purchase Price Allocation, Noncurrent Liabilities, Long-term Debt, Adjusted Share Price Share Price Debt Instrument, Interest Rate, Stated Percentage Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current and Non-Current Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current and Non-Current Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current and Non-Current Assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Assets Business Acquisition, Purchase Price Allocation, Other Assets, Adjusted Business Acquisition, Purchase Price Allocation, Other Assets, Adjusted Business Acquisition, Purchase Price Allocation, Other Assets, Adjusted Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Total Assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Total Assets Business Acquisition, Purchase Price Allocation, Assets Acquired, Adjusted Business Acquisition, Purchase Price Allocation, Assets Acquired, Adjusted Business Acquisition, Purchase Price Allocation, Assets Acquired, Adjusted Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current and Non-Current Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current and Non-Current Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current and Non-Current Liabilities Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Current and Noncurrent Liabilities Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Current and Noncurrent Liabilities Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Current and Noncurrent Liabilities Business Acquisition, Purchase Price Allocation, Current and Non-current Liabilities, Adjusted Business Acquisition, Purchase Price Allocation, Current and Non-current Liabilities, Adjusted Business Acquisition, Purchase Price Allocation, Current and Non-current Liabilities, Adjusted Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities Business Acquisition, Purchase Price Allocation, Liabilities Assumed, Adjusted Business Acquisition, Purchase Price Allocation, Liabilities Assumed, Adjusted Business Acquisition, Purchase Price Allocation, Liabilities Assumed, Adjusted Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual Business Acquisition, Pro Forma Net Income(Loss), Including Portion Attributable to Noncontrolling Interest Business Acquisition, Pro Forma Net Income(Loss), Including Portion Attributable to Noncontrolling Interest Business Acquisition, Pro Forma Net Income(Loss), Including Portion Attributable to Noncontrolling Interest Business Acquisition, Pro Forma Net Income (Loss) Business Acquisition, Pro Forma Net Income (Loss) Business Acquisition, Pro Forma Earnings Per Share, Basic and Diluted Business Acquisition, Pro Forma Earnings Per Share, Basic and Diluted Business Acquisition, Pro Forma Earnings Per Share, Basic and Diluted Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Long-term Debt Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Long-term Debt Other Liabilities Other Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Current and Non-Current Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Current and Non-Current Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Current and Non-Current Liabilities Liabilities Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Net Assets Acquired Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Net Assets Acquired Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Net Assets Acquired Business Acquisition, Purchase Price Allocation, Assets Acquired (Liabilities Assumed), Net Adjusted Business Acquisition, Purchase Price Allocation, Assets Acquired (Liabilities Assumed), Net Adjusted Business Acquisition, Purchase Price Allocation, Assets Acquired (Liabilities Assumed), Net Adjusted Other Comprehensive Income (Loss), Net of Tax Proceeds from Issuance of Common Stock