Fair Value Disclosures [Abstract] Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Income Taxes Disclosure [Abstract] -- None. No documentation exists for this element. -- Income Taxes Income Tax Disclosure [Text Block] Earnings (Loss) Per Share Disclosure [Abstract] -- None. No documentation exists for this element. -- Reconciliation of NRG's basic earnings per share to diluted earnings per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Nature of Business Disclosure [Abstract] -- None. No documentation exists for this element. -- Nature of Business Business Description and Basis of Presentation [Text Block] Stockholders' Equity Note [Abstract] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] NRG Yield LLC NRG Yield LLC [Member] NRG Yield LLC [Member] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] NRG NRG [Member] NRG [Member] Public Shareholders Public Shareholders [Member] Public Shareholders [Member] NRG Yield, Inc. NRG Yield, Inc. [Member] NRG Yield, Inc. [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common Class A Common Class A [Member] Common Class B Common Class B [Member] Class of Stock Class of Stock [Line Items] Common Stock, Shares Authorized Common Stock, Shares Authorized Common Stock, Par Value Per Share Common Stock, Par or Stated Value Per Share Sale of Stock, Number of Shares Issued in Transaction Sale of Stock, Number of Shares Issued in Transaction Proceeds from Issuance of Common Stock Proceeds from Issuance of Common Stock Expense Related to Distribution or Servicing and Underwriting Fees Expense Related to Distribution or Servicing and Underwriting Fees Payments to Acquire Interest in Subsidiaries and Affiliates Payments to Acquire Interest in Subsidiaries and Affiliates Economic Interest in Entity Economic Interest in Entity Economic Interest in Entity 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 Common Stock, Shares, Outstanding Common Stock, Shares, Outstanding Common Stock, Dividends, Per Share, Declared Common Stock, Dividends, Per Share, Declared Common Stock, Dividends, Proposed Quarterly Amount, Per Share Common Stock, Dividends, Proposed Quarterly Amount, Per Share Common Stock, Dividends, Proposed Quarterly Amount, Per Share Common Stock, Dividends, Proposed Annual Amount, Per Share Common Stock, Dividends, Proposed Annual Amount, Per Share Common Stock, Dividends, Proposed Annual Amount, Per Share Preferred Stock, Shares Authorized Preferred Stock, Shares Authorized Preferred Stock, Par or Stated Value Per Share Preferred Stock, Par or Stated Value Per Share Noncontrolling Interest Noncontrolling Interest [Abstract] Noncontrolling interest, balance as of December 31, 2012 Stockholders' Equity Attributable to Noncontrolling Interest Contributions from noncontrolling interest, net of returns of capital Noncontrolling Interest Increase From Contributions From Noncontrolling Interest Holders Amount of increase in noncontrolling interest from contributions from noncontrolling interest holders. Comprehensive income attributable to noncontrolling interest Comprehensive (Income) Loss, Net of Tax, Attributable to Noncontrolling Interest Noncontrolling interest, balance as of September 30, 2013 Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Non-affiliate Non-affiliated entity [Member] Non-affiliated entity [Member] Affiliate Affiliated Entity [Member] Statement Statement [Line Items] ASSETS Assets [Abstract] Current Assets Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash Restricted Cash and Cash Equivalents, Current Accounts receivable Accounts Receivable, Net, Current Inventory Inventory, Net Notes receivable Notes, Loans and Financing Receivable, Net, Current Renewable energy grant receivable Grants Receivable, Current Deferred income taxes Deferred Tax Assets, Net, Current Prepayments and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Property, plant and equipment, net of accumulated depreciation of $134 and $115 Property, Plant and Equipment, Net Other Assets Assets, Noncurrent [Abstract] Equity investments in affiliates Equity Method Investments Notes receivable Notes, Loans and Financing Receivable, Net, Noncurrent Intangible assets, net of accumulated amortization of $6 and $3 Finite-Lived Intangible Assets, Net Derivative instruments Derivative Instruments and Hedges, Noncurrent Deferred income taxes Deferred Tax Assets, Net, Noncurrent Other non-current assets Other Assets, Noncurrent Total other assets Total Other Assets Sum of the carrying amounts as of the balance sheet date of all assets, except for property, plant and equipment, that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer. Total Assets 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 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 Liabilities, Current Other Liabilities Liabilities, Noncurrent [Abstract] Long-term debt Long-term Debt and Capital Lease Obligations Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Derivative instruments Derivative Liability, Noncurrent Other non-current liabilities Other Liabilities, Noncurrent Total non-current liabilities Liabilities, Noncurrent Total Liabilities Liabilities Commitments and Contingencies Commitments and Contingencies Stockholders' Equity Stockholders' Equity Attributable to Parent [Abstract] Members' equity Other Partners' Capital Additional paid-in capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Noncontrolling interest Total Stockholders' Equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total Liabilities and Stockholders’ Equity Liabilities and Equity Statement of Comprehensive Income [Abstract] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Predecessor Predecessor [Member] Successor Successor [Member] Other Comprehensive (Loss)/Income, net of tax Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Net income/(loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Unrealized (loss)/gain on derivatives, net of income tax expense/(benefit) of $1, ($2), $1 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 Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive Income (Loss), Net of Tax, Available for Common Stockholders Comprehensive Income (Loss), Net of Tax, Available for Common Stockholders Comprehensive Income (Loss), Net of Tax, Available for Common Stockholders Related Party Transactions [Abstract] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Management Services Agreement with NRG Management Services Agreement with NRG [Member] Management Services Agreement with NRG [Member] CVSR CVSR [Member] CVSR [Member] Related Party Transaction Related Party Transaction [Line Items] Management Services Fee, Annual Management Services Fee, Quarterly Management Services Fee, Quarterly Cost of Management Services Cost of Management Services Cost of Management Services Due to Affiliate Due to Affiliate Debt Disclosure [Abstract] Schedule of Long-term Debt Schedule of Debt [Table Text Block] Statement of Cash Flows [Abstract] Cash Flows from Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] 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 Depreciation, Depletion 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 Net Cash Provided by (Used in) 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 Increase in restricted cash, net Increase (Decrease) in Restricted Cash Decrease/(increase) in notes receivable 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 Proceeds from Renewable Energy Grants The amount of cash received during the period for renewable energy grants related to capital projects. Investments in unconsolidated affiliates (Investments in) Proceeds From Sales of Unconsolidated Affiliates (Investments in) Proceeds From Sales of Unconsolidated Affiliates Net Cash Used by Investing Activities Net Cash Provided by (Used in) Investing Activities Cash Flows from Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] Capital contributions from NRG Proceeds from Contributions from Parent Dividends and returns of capital to NRG Payments of Capital Distribution Proceeds from issuance of long-term debt — external Proceeds from Issuance of Long-term Debt Payment of debt issuance costs Payments of Debt Issuance Costs Payments for long-term debt Proceeds from (Repayments of) Debt Net Cash Provided by Financing Activities Net Cash Provided by (Used in) Financing Activities Net Increase in Cash and Cash Equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and Cash Equivalents at Beginning of Period Cash and Cash Equivalents at End of Period Effective tax rate Income Tax Expense (Benefit) Continuing Operations [Text Block] Table shows the income tax expense and the related effective tax rate for the period. Earnings Per Share Reconciliation [Abstract] 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 Class A 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 Class A common share — basic and diluted Earnings Per Share, Basic and Diluted Segment Reporting Disclosure [Abstract] -- None. No documentation exists for this element. -- Schedule of Segment Reporting Information, by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Property, Plant and Equipment [Abstract] 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] Avra Valley Avra Valley [Member] Avra Valley [Member] Alpine Alpine [Member] Alpine [Member] Borrego Borrego [Member] Borrego [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] Facilities and equipment Facilities And Equipment [Member] Represents long-lived, depreciable assets of facilities and equipment. Land and improvements Land and Land Improvements [Member] Construction in progress Construction in Progress [Member] Property, Plant and Equipment Property, Plant and Equipment [Line Items] Property, plant and equipment, gross Property, Plant and Equipment, Gross Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property, plant and equipment, net Renewable energy grant, gross Renewable energy grant, gross Renewable energy grant, gross 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 Property, plant and equipment, useful life Property, Plant and Equipment, Useful Life Accounting for Derivative Instruments and Hedging Activities Disclosure [Abstract] -- None. No documentation exists for this element. -- 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 Schedule of Offsetting Assets and Liabilities [Table Text Block] Schedule of Offsetting Assets and 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] 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] Earnings Per Share Earnings Per Share [Text Block] Document And Entity Information [Abstract] -- None. No documentation exists for this element. -- 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 Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Significant Accounting Policies [Abstract] Significant Accounting Policies [Abstract] Use of Estimates (Policy) Use of Estimates [Policy Text Block] Describes an entity's accounting policy regarding estimates used in the preparation of financial statements in conformity with generally accepted accounting principles, which requires the use of management estimates. Segment Reporting (Policy) Segment Reporting, Policy [Policy Text Block] Accounting for Derivative Instruments and Hedging Activities Derivative Instruments and Hedging Activities Disclosure [Text Block] Derivative [Table] Derivative [Table] 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 Natural Gas [Member] Details pertaining to the natural gas, which is considered as a derivative commodity. Interest Interest [Member] Details pertaining to interest rate swaps which are considered a derivative commodity. Derivatives, Fair Value, by Derivative Instrument Risk [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] 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. Commodity contracts Commodity Contract [Member] Interest rate contracts Interest Rate Contract [Member] 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] Underlying, Derivative Underlying, Derivative Derivative, Notional Amount Derivative, Notional Amount Fair Value of Derivative Instruments Derivative, Fair Value, Net [Abstract] Derivative Assets Derivative Asset, Fair Value, Gross Asset Derivative Liabilities Derivative Liability, Fair Value, Gross Liability 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 Liability, Fair Value, Amount Offset Against Collateral Derivative Liability, Fair Value, Amount Offset Against Collateral Derivative Asset, Fair Value, Amount Offset Against Collateral Derivative Asset, 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 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 Reclassified from accumulated OCL to income due to realization of previously deferred amounts Mark-to-market of cash flow hedge accounting contracts Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net Accumulated OCL ending balance, net of income tax benefit of $1 and $14, respectively Accumulated OCL attributable to noncontrolling interest Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax, Attributable to Noncontrolling Interest Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax, Attributable to Noncontrolling Interest Accumulated OCI ending balance, income tax of $1 and $14, 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 Loss expected to be realized from OCI during the next 12 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. 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 Variable Interest Entities Disclosure [Abstract] -- None. No documentation exists for this element. -- Summarized unaudited financial information for GCE Holdings LLC Schedule of Unaudited Fnancial Information [Table Text Block] Schedule of Unaudited Fnancial Information [Table Text Block] Related Party Transactions Disclosure Related Party Transactions Disclosure [Text Block] Segment Reporting Segment Reporting Disclosure [Text Block] Income Statement [Abstract] Operating Revenues Revenues [Abstract] Total operating revenues Revenues Operating Costs and Expenses Operating Costs and Expenses [Abstract] Cost of operations Cost of Revenue Depreciation and amortization General and administrative — affiliate General and Administrative Expense Total operating costs and expenses Costs and Expenses Operating Income Operating Income (Loss) Other Income/(Expense) Costs and Expenses [Abstract] Equity in earnings of unconsolidated affiliates Income (Loss) from Equity Method Investments Other income, net Other Nonoperating Income (Expense) Interest expense Interest Expense Total other income/(expense) Nonoperating Income (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 Less: Net income attributable to noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Earnings Per Share Attributable to NRG Yield, Inc. Class A Common Stockholders Earnings Per Share [Abstract] Unrealized gain/loss on derivatives, income tax expense /(benefit) Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Income Tax Contingency [Table] Income Tax Contingency [Table] Income Taxes Income Tax Contingency [Line Items] Income before income taxes Income tax expense Effective tax rate (as a percent) Effective Income Tax Rate Reconciliation, Percent Statutory income tax rate (as a percent) Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Adjustment to additional paid-in capital for tax basis differences Adjustment to additional paid-in capital for tax basis differences Adjustment to additional paid-in capital for tax basis differences Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Fair Value Asset and Liabilities, Measured on Recurring Basis Unobservable Input, Changes by Asset Type [Axis] Fair Value Asset and Liabilities, Measured on Recurring Basis Unobservable Input, Changes by Asset Type [Axis] This element provides the group of categories of assets and liabilities for which the change in the balance of the fair value measurement using significant unobservable inputs (level 3) is being disclosed. Fair Value Asset and Liabilities, Measured on Recurring Basis Unobservable Input, Changes Asset Types [Domain] Fair Value Asset and Liabilities, Measured on Recurring Basis Unobservable Input, Changes Asset Types [Domain] This element provides general categories of assets and liabilities for which the change in the balance of the fair value measurement using significant unobservable inputs (level 3) is being disclosed. Derivative [Member] Derivative [Member] Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Measurement Basis [Axis] Fair Value, Disclosure Item Amounts [Domain] Fair Value Measurement [Domain] Carrying Amount Reported Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring Fair Value, Measurements, Recurring [Member] Fair Value Assets and Liabilities, Measured on Recurring Basis, Disclosure Items [Axis] Fair Value Assets and Liabilities, Measured on Recurring Basis, Disclosure Items [Axis] Represents a number of concepts which are required or desirable disclosure items concerning assets and liabilities, including [financial] instruments that are classified in stockholders' equity, which are measured at fair value on a recurring basis. Fair Value Assets and Liabilities, Measured on Recurring Basis, Disclosure Items [Domain] Fair Value Assets and Liabilities, Measured on Recurring Basis, Disclosure Items [Domain] Represents a number of concepts which are required or desirable disclosure items concerning assets and liabilities, including [financial] instruments that are classified in stockholders' equity, which are measured at fair value on a recurring basis. Fair Value, Inputs, Level 1 Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 Fair Value, Inputs, Level 3 [Member] Fair Value of Financial Instruments Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Notes receivable Financing Receivable, Gross Long-term debt, including current portion Long-term Debt Derivative Liabilities Fair Value, Assets And Liabilities, Level 1 to Level 2 Transfers, Amount Fair Value, Assets And Liabilities, Level 1 to Level 2 Transfers, Amount Amount of transfers of assets and liabilities measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2. Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset And Liability Value Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset And Liability Value This element represents an assets and liabilities measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset and Liability, Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset and Liability, Purchases Purchases that have taken place during the period in relation to assets and liabilities measured at fair value and categorized within Level 3 of the fair value hierarchy. Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Derivative Asset, Fair Value Determined Using Valuation Techniques (as a percent) 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. Derivative Liability, Fair Value Determined Using Valuation Techniques (as a percent) Derivative Liability, Fair Value Determined Using Valuation Techniques, Percentage Derivative Liability, Fair Value Determined Using Valuation Techniques, Percentage 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 Property, plant and equipment, accumulated depreciation Intangible assets, accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Business Combinations [Abstract] Business Acquisition Mergers, Acquisitions and Dispositions Disclosures [Text Block] Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Marsh Landing Term Loan Facility Marsh Landing Term Loan Facility [Member] Marsh Landing Term Loan Facility [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Marsh Landing Marsh Landing [Member] Marsh Landing [Member] Business Acquisition Business Acquisition [Line Items] Business Acquisition, Percentage of Voting Interests Acquired Business Acquisition, Percentage of Voting Interests Acquired 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 Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Maximum Borrowing Capacity 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 Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, 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, Assets Acquired (Liabilities Assumed), Net Adjusted Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Long-term Debt Long-term Debt [Text Block] Schedule of Stock by Class Schedule of Stock by Class [Table Text Block] Schedule of Change in Noncontrolling Interest Schedule of Change in Noncontrolling Interest [Table Text Block] Schedule of Change in Noncontrolling Interest [Table Text Block] Estimated carrying values and fair values of the Company's recorded financial instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Assets and liabilities measured and recorded at fair value on the consolidated balance sheets on a recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [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] Property, Plant and Equipment Disclosure Property, Plant and Equipment Disclosure [Text Block] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] 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] Operating revenues Cost of operations Operating Expenses Equity in earnings of unconsolidated affiliates Income/(loss) before income taxes Total assets Nature of Business [Table] Nature of Business [Table] Nature of Business [Table] GenConn Middletown GenConn Middletown [Member] GenConn Middletown [Member] GenConn Devon GenConn Devon [Member] GenConn Devon [Member] Avenal Avenal [Member] Avenal [Member] Blythe 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] 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] South Trent South Trent Holding LLC [Member] South Trent Holding LLC [Member] Class A units of NRG Yield LLC Capital Unit, Class A [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. Conventional Utility-Scale Solar Utility-Scale Solar [Member] Utility-Scale Solar [Member] 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] Sale of Stock, Number of Shares Acquired in Transaction Sale of Stock, Number of Shares Acquired in Transaction Sale of Stock, Number of Shares Acquired in Transaction Common Stock, Voting Interest Common Stock, Voting Interest Common Stock, Voting Interest Proceeds from Issuance Initial Public Offering Proceeds from Issuance Initial Public Offering Percentage of Ownership Percentage of Ownership Percentage of Ownership 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. Power Generation Capacity, Reached Commercial Operations, Megawatts Power Generation Capacity, Reached Commercial Operations, Megawatts Power Generation Capacity, Reached Commercial Operations, Megawatts Allocation of Corporate Expenses Allocation of Corporate Expenses Allocation of Corporate Expenses Management Fee Expense Management Fee Expense Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] NRG Marsh Landing LLC, due 2017 and 2023 NRG Marsh Landing LLC, due 2017 Marsh Landing Term Loan Due 2017 [Member] Marsh Landing Term Loan Due 2017 [Member] NRG Marsh Landing LLC, due 2023 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 2013 Alpine Financing Agreement, due 2013 [Member] Alpine Financing Agreement, due 2013 [Member] NRG Solar Alpine, due 2022 Alpine Financing Agreement, due 2022 [Member] Alpine Financing Agreement, due 2022 [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 2013 NRG Energy Center Minneapolis LLC Senior Secured Notes, due 2013 [Member] NRG Energy Center Minneapolis LLC Senior Secured Notes, due 2013 [Member] 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] 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] NRG Roadrunner LLC, due 2031 Roadrunner Financing Agreement [Member] Roundrunner Financing Agreement [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 [Member] NRG Energy Center Princeton LLC, due 2017 [Member] NRG Energy Center Princeton LLC, due 2017 [Member] Note payable to NRG Energy, Inc. - South Trent 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] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Letter of Credit Letter of Credit [Member] Fixed Rate Notes Fixed Rate Notes [Member] Fixed Rate Notes [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] Promissory Note Promissory Note [Member] Promissory Note [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] London Interbank Offered Rate (LIBOR) London Interbank Offered Rate (LIBOR) [Member] Interest Rate Swaps Interest Rate Swap [Member] Long-term Debt Disclosure Debt Instrument [Line Items] Long-term Debt Total long-term debt Long-term Debt, Excluding Current Maturities Variable rate basis Debt Instrument, Description of Variable Rate Basis Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Interest rate Debt Instrument, Interest Rate, Stated Percentage Long-term Debt, Current Maturities Long-term Debt, Current Maturities Interest rate, minimum Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum Interest rate, maximum Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum Credit Facility, Maximum Borrowing Capacity, Amendment Credit Facility, Maximum Borrowing Capacity, Amendment Credit Facility, Maximum Borrowing Capacity, Amendment Line of Credit Facility, Increase, Additional Borrowings Proceeds from Lines of Credit Letters of Credit Outstanding, Amount Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings Proceeds from Contributions from Parent Debt Instrument, Face Amount Debt Instrument, Face Amount Debt Instrument, Escalation Percent of Basis Spread on Variable Rate Debt Instrument, Escalation Percent of Basis Spread on Variable Rate Debt Instrument, Escalation Percent of Basis Spread on Variable Rate Letters Of Credit, Availability Fee, Percentage Of Applicable Margin Letters Of Credit, Availability Fee, Percentage Of Applicable Margin Letters of Credit, Availability Fee, Percentage of Applicable Margin Number of Interest Rate Derivatives Held Number of Interest Rate Derivatives Held Derivative, Minimum Percent of Outstanding Notional Amount Required to Have Fixed Interest Rate Derivative, Minimum Percent of Outstanding Notional Amount Required to Have Fixed Interest Rate Derivative, Minimum Percent of Outstanding Notional Amount Required to Have Fixed Interest Rate Derivative, Fixed Interest Rate Derivative, Fixed Interest Rate Notional Amount of Interest Rate Derivatives Promissory Note Conversion into Equity Promissory Note Conversion into Equity Promissory Note Conversion into Equity Variable Interest Entity Variable Interest Entity [Text Block] Variable Interest Entity [Text Block] Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Working Capital Facility Working Capital Facility [Member] Working Capital Facility [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 Energy LLC Gen Conn Energy LLC [Member] Represents the information pertaining to GenConn Energy LLC. Equity Method Investee, Name [Axis] Investment, Name [Axis] Equity Method Investee, Name [Domain] Investment, Name [Domain] GCE Holdings LLC GCE Holding LLC [Member] Represents the GCE Holding LLC GCE Holding LLC which wholly-owns GenConn Energy LLC. GenConn Energy LLC Variable Interest Entity Variable Interest Entity [Line Items] Economic interest in equity method investments (as a percent) Equity Method Investment, Ownership Percentage Power generation units 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. Operating income Current assets Non-current assets Assets, Noncurrent Current liabilities Non-current liabilities Schedule of Property, Plant and Equipment Property, Plant and Equipment [Table Text Block]