2.4.0.6 Html 490 346 1 true 132 0 false 20 false false R1.htm 0001000 - Document - Document and Entity Information Sheet http://www.nrgenergy.com/role/DocumentAndEntityInformation Document and Entity Information false false R2.htm 1001000 - Statement - Condensed Consolidated Statements of Operations Sheet http://www.nrgenergy.com/role/CondensedConsolidatedStatementsOfOperations Condensed Consolidated Statements of Operations false false R3.htm 1002000 - Statement - Condensed Consolidated Statements of Comprehensive Loss Income Sheet http://www.nrgenergy.com/role/CondensedConsolidatedStatementsOfComprehensiveLossIncome Condensed Consolidated Statements of Comprehensive Loss Income false false R4.htm 1002001 - Statement - Condensed Consolidated Statement of Comprehensive Loss Income (Parenthetical) Sheet http://www.nrgenergy.com/role/CondensedConsolidatedStatementOfComprehensiveLossIncomeParenthetical Condensed Consolidated Statement of Comprehensive Loss Income (Parenthetical) true false R5.htm 1003000 - Statement - Condensed Consolidated Balance Sheets Sheet http://www.nrgenergy.com/role/CondensedConsolidatedBalanceSheets Condensed Consolidated Balance Sheets false false R6.htm 1003501 - Statement - Condensed Consolidated Balance Sheets (Parenthetical) Sheet http://www.nrgenergy.com/role/CondensedConsolidatedBalanceSheetsParenthetical Condensed Consolidated Balance Sheets (Parenthetical) false false R7.htm 1004000 - Statement - Condensed Consolidated Statements Of Cash Flows Sheet http://www.nrgenergy.com/role/CondensedConsolidatedStatementsOfCashFlows Condensed Consolidated Statements Of Cash Flows false false R8.htm 2101100 - Disclosure - Basis of Presentation Sheet http://www.nrgenergy.com/role/BasisOfPresentation Basis of Presentation false false R9.htm 2104100 - Disclosure - Business Acquisitions and Dispositions Sheet http://www.nrgenergy.com/role/BusinessAcquisitionsAndDispositions Business Acquisitions and Dispositions false false R10.htm 2105100 - Disclosure - Nuclear Innovation North America LLC Developments Sheet http://www.nrgenergy.com/role/NuclearInnovationNorthAmericaLlcDevelopments Nuclear Innovation North America LLC Developments false false R11.htm 2106100 - Disclosure - Fair Value of Financial Instruments Sheet http://www.nrgenergy.com/role/FairValueOfFinancialInstruments Fair Value of Financial Instruments false false R12.htm 2107100 - Disclosure - Nuclear Decommissioning Trust Fund Sheet http://www.nrgenergy.com/role/NuclearDecommissioningTrustFund Nuclear Decommissioning Trust Fund false false R13.htm 2112100 - Disclosure - Accounting for Derivative Instruments and Hedging Activities Sheet http://www.nrgenergy.com/role/AccountingForDerivativeInstrumentsAndHedgingActivities Accounting for Derivative Instruments and Hedging Activities false false R14.htm 2114100 - Disclosure - Debt and Capital Leases Sheet http://www.nrgenergy.com/role/DebtAndCapitalLeases Debt and Capital Leases false false R15.htm 2116100 - Disclosure - Variable Interest Entities, or VIEs Sheet http://www.nrgenergy.com/role/VariableInterestEntitiesOrVies Variable Interest Entities, or VIEs false false R16.htm 2117100 - Disclosure - Changes in Capital Structure Sheet http://www.nrgenergy.com/role/ChangesInCapitalStructure Changes in Capital Structure false false R17.htm 2119100 - Disclosure - (Loss) Earnings Per Share Sheet http://www.nrgenergy.com/role/LossEarningsPerShare (Loss) Earnings Per Share false false R18.htm 2121100 - Disclosure - Segment Reporting Sheet http://www.nrgenergy.com/role/SegmentReporting Segment Reporting false false R19.htm 2124100 - Disclosure - Income Taxes Sheet http://www.nrgenergy.com/role/IncomeTaxes Income Taxes false false R20.htm 2132100 - Disclosure - Commitments and Contingencies Sheet http://www.nrgenergy.com/role/CommitmentsAndContingencies Commitments and Contingencies false false R21.htm 2135100 - Disclosure - Regulatory Matters Sheet http://www.nrgenergy.com/role/RegulatoryMatters Regulatory Matters false false R22.htm 2136100 - Disclosure - Environmental Matters Sheet http://www.nrgenergy.com/role/EnvironmentalMatters Environmental Matters false false R23.htm 2138100 - Disclosure - Condensed Consolidating Financial Information Sheet http://www.nrgenergy.com/role/CondensedConsolidatingFinancialInformation Condensed Consolidating Financial Information false false R24.htm 2201200 - Disclosure - Summary of Significant Accounting Policies (Policy) Sheet http://www.nrgenergy.com/role/SummaryOfSignificantAccountingPoliciesPolicy Summary of Significant Accounting Policies (Policy) false false R25.htm 2301301 - Disclosure - Significant Accounting Policies Noncontrolling Interest (Tables) Sheet http://www.nrgenergy.com/role/SignificantAccountingPoliciesNoncontrollingInterestTables Significant Accounting Policies Noncontrolling Interest (Tables) false false R26.htm 2306301 - Disclosure - Fair Value of Financial Instruments (Tables) Sheet http://www.nrgenergy.com/role/FairValueOfFinancialInstrumentsTables Fair Value of Financial Instruments (Tables) false false R27.htm 2307301 - Disclosure - Nuclear Decommissioning Trust Fund (Tables) Sheet http://www.nrgenergy.com/role/NuclearDecommissioningTrustFundTables Nuclear Decommissioning Trust Fund (Tables) false false R28.htm 2312301 - Disclosure - Accounting for Derivative Instruments and Hedging Activities (Tables) Sheet http://www.nrgenergy.com/role/AccountingForDerivativeInstrumentsAndHedgingActivitiesTables Accounting for Derivative Instruments and Hedging Activities (Tables) false false R29.htm 2314302 - Disclosure - Debt and Capital Leases (Tables) Sheet http://www.nrgenergy.com/role/DebtAndCapitalLeasesTables Debt and Capital Leases (Tables) false false R30.htm 2317301 - Disclosure - Changes in Capital Structure (Tables) Sheet http://www.nrgenergy.com/role/ChangesInCapitalStructureTables Changes in Capital Structure (Tables) false false R31.htm 2319301 - Disclosure - (Loss) Earnings Per Share (Tables) Sheet http://www.nrgenergy.com/role/LossEarningsPerShareTables (Loss) Earnings Per Share (Tables) false false R32.htm 2321301 - Disclosure - Segment Reporting (Tables) Sheet http://www.nrgenergy.com/role/SegmentReportingTables Segment Reporting (Tables) false false R33.htm 2324301 - Disclosure - Income Taxes (Tables) Sheet http://www.nrgenergy.com/role/IncomeTaxesTables Income Taxes (Tables) false false R34.htm 2338301 - Disclosure - Condensed Consolidating Financial Information (Tables) Sheet http://www.nrgenergy.com/role/CondensedConsolidatingFinancialInformationTables Condensed Consolidating Financial Information (Tables) false false R35.htm 2401402 - Disclosure - Summary of Significant Accounting Policies (Details) Sheet http://www.nrgenergy.com/role/SummaryOfSignificantAccountingPoliciesDetails Summary of Significant Accounting Policies (Details) false false R36.htm 2404401 - Disclosure - Business Acquisitions and Dispositions (Details) Sheet http://www.nrgenergy.com/role/BusinessAcquisitionsAndDispositionsDetails Business Acquisitions and Dispositions (Details) false false R37.htm 2405401 - Disclosure - Nuclear Innovation North America LLC Developments (Details) Sheet http://www.nrgenergy.com/role/NuclearInnovationNorthAmericaLlcDevelopmentsDetails Nuclear Innovation North America LLC Developments (Details) false false R38.htm 2406402 - Disclosure - Fair Value of Financial Instruments (Details) Sheet http://www.nrgenergy.com/role/FairValueOfFinancialInstrumentsDetails Fair Value of Financial Instruments (Details) false false R39.htm 2406403 - Disclosure - Fair Value of Financial Instruments (Details 2) Sheet http://www.nrgenergy.com/role/FairValueOfFinancialInstrumentsDetails2 Fair Value of Financial Instruments (Details 2) false false R40.htm 2406404 - Disclosure - Fair Value of Financial Instruments (Details 3) Sheet http://www.nrgenergy.com/role/FairValueOfFinancialInstrumentsDetails3 Fair Value of Financial Instruments (Details 3) false false R41.htm 2406405 - Disclosure - Fair Value of Financial Instruments (Details 4) Sheet http://www.nrgenergy.com/role/FairValueOfFinancialInstrumentsDetails4 Fair Value of Financial Instruments (Details 4) false false R42.htm 2407402 - Disclosure - Nuclear Decommissioning Trust Fund (Details) Sheet http://www.nrgenergy.com/role/NuclearDecommissioningTrustFundDetails Nuclear Decommissioning Trust Fund (Details) false false R43.htm 2412402 - Disclosure - Accounting for Derivative Instruments and Hedging Activities (Details) Sheet http://www.nrgenergy.com/role/AccountingForDerivativeInstrumentsAndHedgingActivitiesDetails Accounting for Derivative Instruments and Hedging Activities (Details) false false R44.htm 2412403 - Disclosure - Accounting for Derivative Instruments and Hedging Activities (Details 2) Sheet http://www.nrgenergy.com/role/AccountingForDerivativeInstrumentsAndHedgingActivitiesDetails2 Accounting for Derivative Instruments and Hedging Activities (Details 2) false false R45.htm 2414401 - Disclosure - Debt and Capital Leases (Details) Sheet http://www.nrgenergy.com/role/DebtAndCapitalLeasesDetails Debt and Capital Leases (Details) false false R46.htm 2416401 - Disclosure - Variable Interest Entities, or VIEs (Details) Sheet http://www.nrgenergy.com/role/VariableInterestEntitiesOrViesDetails Variable Interest Entities, or VIEs (Details) false false R47.htm 2417402 - Disclosure - Changes in Capital Structure (Details) Sheet http://www.nrgenergy.com/role/ChangesInCapitalStructureDetails Changes in Capital Structure (Details) false false R48.htm 2417403 - Disclosure - Changes in Capital Structure (Details 2) Sheet http://www.nrgenergy.com/role/ChangesInCapitalStructureDetails2 Changes in Capital Structure (Details 2) false false R49.htm 2419402 - Disclosure - (Loss) Earnings Per Share (Details) Sheet http://www.nrgenergy.com/role/LossEarningsPerShareDetails (Loss) Earnings Per Share (Details) false false R50.htm 2421402 - Disclosure - Segment Reporting (Details) Sheet http://www.nrgenergy.com/role/SegmentReportingDetails Segment Reporting (Details) false false R51.htm 2424402 - Disclosure - Income Taxes (Details) Sheet http://www.nrgenergy.com/role/IncomeTaxesDetails Income Taxes (Details) false false R52.htm 2424403 - Disclosure - Income Taxes (Details 2) Sheet http://www.nrgenergy.com/role/IncomeTaxesDetails2 Income Taxes (Details 2) false false R53.htm 2432401 - Disclosure - Commitments and Contingencies (Details) Sheet http://www.nrgenergy.com/role/CommitmentsAndContingenciesDetails Commitments and Contingencies (Details) false false R54.htm 2435401 - Disclosure - Regulatory Matters (Details) Sheet http://www.nrgenergy.com/role/RegulatoryMattersDetails Regulatory Matters (Details) false false R55.htm 2436401 - Disclosure - Environmental Matters (Details) Sheet http://www.nrgenergy.com/role/EnvironmentalMattersDetails Environmental Matters (Details) false false R56.htm 2438402 - Disclosure - Condensed Consolidating Financial Information (Details) Sheet http://www.nrgenergy.com/role/CondensedConsolidatingFinancialInformationDetails Condensed Consolidating Financial Information (Details) false false R57.htm 2438403 - Disclosure - Condensed Consolidating Financial Information (Details 2) Sheet http://www.nrgenergy.com/role/CondensedConsolidatingFinancialInformationDetails2 Condensed Consolidating Financial Information (Details 2) false false R58.htm 2438404 - Disclosure - Condensed Consolidating Financial Information (Details 3) Sheet http://www.nrgenergy.com/role/CondensedConsolidatingFinancialInformationDetails3 Condensed Consolidating Financial Information (Details 3) false false R59.htm 2438405 - Disclosure - Condensed Consolidating Financial Information (Details 4) Sheet http://www.nrgenergy.com/role/CondensedConsolidatingFinancialInformationDetails4 Condensed Consolidating Financial Information (Details 4) false false R60.htm 2438406 - Disclosure - Condensed Consolidating Financial Information (Details 5) Sheet http://www.nrgenergy.com/role/CondensedConsolidatingFinancialInformationDetails5 Condensed Consolidating Financial Information (Details 5) false false All Reports Book All Reports Element us-gaap_DebtInstrumentBasisSpreadOnVariableRate had a mix of decimals attribute values: 0 4. Element us-gaap_DebtInstrumentInterestRateStatedPercentage had a mix of decimals attribute values: 0 4. Element us-gaap_EffectiveIncomeTaxRateContinuingOperations had a mix of decimals attribute values: 0 3. Element us-gaap_LongTermDebt had a mix of decimals attribute values: -6 0. 'Monetary' elements on report '2406402 - Disclosure - Fair Value of Financial Instruments (Details)' had a mix of different decimal attribute values. 'Monetary' elements on report '2406405 - Disclosure - Fair Value of Financial Instruments (Details 4)' had a mix of different decimal attribute values. 'Monetary' elements on report '2414401 - Disclosure - Debt and Capital Leases (Details)' had a mix of different decimal attribute values. 'Monetary' elements on report '2432401 - Disclosure - Commitments and Contingencies (Details)' had a mix of different decimal attribute values. Process Flow-Through: 1001000 - Statement - Condensed Consolidated Statements of Operations Process Flow-Through: 1002000 - Statement - Condensed Consolidated Statements of Comprehensive Loss Income Process Flow-Through: 1002001 - Statement - Condensed Consolidated Statement of Comprehensive Loss Income (Parenthetical) Process Flow-Through: 1003000 - Statement - Condensed Consolidated Balance Sheets Process Flow-Through: Removing column 'Sep. 30, 2011' Process Flow-Through: Removing column 'Dec. 31, 2010' Process Flow-Through: 1003501 - Statement - Condensed Consolidated Balance Sheets (Parenthetical) Process Flow-Through: Removing column 'Sep. 30, 2011' Process Flow-Through: 1004000 - Statement - Condensed Consolidated Statements Of Cash Flows nrg-20120930.xml nrg-20120930.xsd nrg-20120930_cal.xml nrg-20120930_def.xml nrg-20120930_lab.xml nrg-20120930_pre.xml true true