$nrg 2014 Q4 10-K

Concept	2014 Q4	2014 Q3	2014 Q2
Revenue	$4.192B	$4.569B	$3.621B
YoY Change	49.98%	30.92%	23.63%
Cost Of Revenue	$2.951B	$3.278B	$2.828B
YoY Change	51.8%	38.14%	37.88%
Gross Profit	$1.241B	$1.291B	$793.0M
YoY Change	45.83%	15.58%	-9.68%
Gross Profit Margin	29.6%	28.26%	21.9%
Selling, General & Admin	$290.0M	$258.0M	$257.0M
YoY Change	28.89%	21.13%	11.74%
% of Gross Profit	23.37%	19.98%	32.41%
Research & Development	$29.00M	$22.00M	$21.00M
YoY Change	38.1%	-8.33%	0.0%
% of Gross Profit	2.34%	1.7%	2.65%
Depreciation & Amortization	$452.0M	$375.0M	$386.0M
YoY Change	54.79%	14.68%	23.32%
% of Gross Profit	36.42%	29.05%	48.68%
Operating Expenses	$746.0M	$280.0M	$278.0M
YoY Change	34.41%	18.14%	10.76%
Operating Profit	$453.0M	$549.0M	$89.00M
YoY Change	-320.98%	4.17%	-68.99%
Interest Expense	-$293.0M	$280.0M	$274.0M
YoY Change	35.02%	22.81%	33.01%
% of Operating Profit	-64.68%	51.0%	307.87%
Other Income/Expense, Net	$9.000M	-$278.0M	-$295.0M
YoY Change	125.0%	21.4%	34.7%
Pretax Income	$168.0M	$271.0M	-$206.0M
YoY Change	-132.5%	-9.06%	-402.94%
Income Tax	$71.00M	$89.00M	-$126.0M
% Of Pretax Income	42.26%	32.84%
Net Earnings	$119.0M	$168.0M	-$97.00M
YoY Change	-140.07%	41.18%	-178.23%
Net Earnings / Revenue	2.84%	3.68%	-2.68%
Basic Earnings Per Share	$0.21	$0.49	-$0.30
Diluted Earnings Per Share	$0.20	$0.48	-$0.30
COMMON SHARES
Basic Shares Outstanding	338.0M shares	338.0M shares	337.0M shares
Diluted Shares Outstanding	342.0M shares	343.0M shares	337.0M shares

Concept	2014 Q4	2014 Q3	2014 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments	$2.116B	$1.953B	$1.481B
YoY Change	-6.12%	-8.27%	8.26%
Cash & Equivalents	$2.116B	$2.164B	$1.481B
Short-Term Investments
Other Short-Term Assets	$3.588B	$2.700B	$3.184B
YoY Change	33.33%	5.97%	3.85%
Inventory	$1.247B	$1.051B	$996.0M
Prepaid Expenses
Receivables	$1.322B	$1.554B	$1.482B
Other Receivables	$135.0M	$614.0M	$614.0M
Total Short-Term Assets	$8.408B	$7.872B	$7.757B
YoY Change	10.69%	8.59%	11.72%
LONG-TERM ASSETS
Property, Plant & Equipment	$22.37B	$22.18B	$21.58B
YoY Change	12.67%	7.67%	5.49%
Goodwill	$2.574B	$2.452B	$2.116B
YoY Change	29.67%	25.55%	8.29%
Intangibles
YoY Change
Long-Term Investments	$771.0M	$797.0M	$865.0M
YoY Change	70.2%	27.32%	35.37%
Other Assets	$1.045B	$1.281B	$1.307B
YoY Change	41.22%	85.92%	126.12%
Total Long-Term Assets	$9.691B	$10.02B	$29.87B
YoY Change	50.13%	-63.73%	8.43%
TOTAL ASSETS
Total Short-Term Assets	$8.408B	$7.872B	$7.757B
Total Long-Term Assets	$9.691B	$10.02B	$29.87B
Total Assets	$40.47B	$40.07B	$37.63B
YoY Change	19.36%	14.93%	9.09%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$1.060B	$1.098B	$1.103B
YoY Change	2.12%	-3.68%	-7.78%
Accrued Expenses	$805.0M	$1.200B	$1.065B
YoY Change	21.05%	16.17%	28.0%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$474.0M	$854.0M	$833.0M
YoY Change	-54.86%	-6.26%	13.03%
Total Short-Term Liabilities	$4.859B	$4.543B	$4.746B
YoY Change	15.58%	3.67%	7.59%
LONG-TERM LIABILITIES
Long-Term Debt	$19.70B	$19.92B	$18.17B
YoY Change	24.95%	26.05%	14.32%
Other Long-Term Liabilities	$847.0M	$1.385B	$1.254B
YoY Change	21.87%	0.58%	-11.5%
Total Long-Term Liabilities	$23.62B	$23.56B	$21.66B
YoY Change	24.45%	21.75%	10.9%
TOTAL LIABILITIES
Total Short-Term Liabilities	$4.859B	$4.543B	$4.746B
Total Long-Term Liabilities	$23.62B	$23.56B	$21.66B
Total Liabilities	$28.48B	$28.10B	$26.40B
YoY Change	22.84%	18.41%	10.29%
SHAREHOLDERS EQUITY
Retained Earnings	$3.588B	$3.564B	$3.445B
YoY Change	-2.9%	-16.57%	-17.56%
Common Stock	$8.331B	$8.318B	$8.307B
YoY Change	6.21%	6.0%	9.03%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$1.983B	$1.939B	$1.940B
YoY Change	2.11%	-0.15%	-0.21%
Treasury Stock Shares	78.84M shares	77.22M shares	77.28M shares
Shareholders Equity	$10.05B	$10.19B	$10.07B
YoY Change
Total Liabilities & Shareholders Equity	$40.47B	$40.07B	$37.63B
YoY Change	19.36%	14.93%	9.09%

Concept	2014 Q4	2014 Q3	2014 Q2
OPERATING ACTIVITIES
Net Income	$119.0M	$168.0M	-$97.00M
YoY Change	-140.07%	41.18%	-178.23%
Depreciation, Depletion And Amortization	$452.0M	$375.0M	$386.0M
YoY Change	54.79%	14.68%	23.32%
Cash From Operating Activities	$396.0M	$744.0M	-$21.00M
YoY Change	-11.41%	-17.43%	-145.65%
INVESTING ACTIVITIES
Capital Expenditures	-$234.0M	-$168.0M	-$270.0M
YoY Change	-42.36%	-44.0%	-42.31%
Acquisitions
YoY Change
Other Investing Activities	$289.0M	-$1.037B	-$1.607B
YoY Change	-417.58%	191.29%	2163.38%
Cash From Investing Activities	$55.00M	-$1.205B	-$1.877B
YoY Change	-111.07%	83.69%	248.24%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-276.0M	907.0M	218.0M
YoY Change	-256.82%	76.12%	39.74%
NET CHANGE
Cash From Operating Activities	396.0M	744.0M	-21.00M
Cash From Investing Activities	55.00M	-1.205B	-1.877B
Cash From Financing Activities	-276.0M	907.0M	218.0M
Net Change In Cash	175.0M	446.0M	-1.680B
YoY Change	38.89%	-41.32%	398.52%
FREE CASH FLOW
Cash From Operating Activities	$396.0M	$744.0M	-$21.00M
Capital Expenditures	-$234.0M	-$168.0M	-$270.0M
Free Cash Flow	$630.0M	$912.0M	$249.0M
YoY Change	-26.14%	-24.06%	-51.56%

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2015	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2015	dei	Amendment Flag AmendmentFlag	false
CY2015	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2015	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2015
CY2015	nrg	Accrued Expenses And Other Current Liabilities Operating AccruedExpensesAndOtherCurrentLiabilitiesOperating	-9000000	USD
CY2013Q4	nrg	Accumulated Other Comprehensive Income Loss Cumulative Change In Gain Loss From Cash Flow Hedges Tax Amount AccumulatedOtherComprehensiveIncomeLossCumulativeChangeInGainLossFromCashFlowHedgesTaxAmount	14000000	USD
CY2015Q4	nrg	Amount Of Net Counterparty Credit Risk Exposure To Certain Counterparties AmountOfNetCounterpartyCreditRiskExposureToCertainCounterparties	247000000	USD
CY2014Q4	nrg	Accumulated Other Comprehensive Income Loss Cumulative Change In Gain Loss From Cash Flow Hedges Tax Amount AccumulatedOtherComprehensiveIncomeLossCumulativeChangeInGainLossFromCashFlowHedgesTaxAmount	35000000	USD
CY2015Q4	nrg	Accumulated Other Comprehensive Income Loss Cumulative Change In Gain Loss From Cash Flow Hedges Tax Amount AccumulatedOtherComprehensiveIncomeLossCumulativeChangeInGainLossFromCashFlowHedgesTaxAmount	16000000	USD
CY2015	dei	Document Period End Date DocumentPeriodEndDate	2016-12-31
CY2015	dei	Document Type DocumentType	10-K
CY2015	dei	Entity Central Index Key EntityCentralIndexKey	0001013871
CY2016Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	314890647	shares
CY2015	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2015	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2015Q2	dei	Entity Public Float EntityPublicFloat	6713289371	USD
CY2015	dei	Entity Registrant Name EntityRegistrantName	NRG ENERGY, INC.
CY2015	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2015	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2014Q4	nrg	Accrued Expenses And Other Current Liabilities AccruedExpensesAndOtherCurrentLiabilities	1199000000	USD
CY2013	nrg	Accrued Expenses And Other Current Liabilities Operating AccruedExpensesAndOtherCurrentLiabilitiesOperating	-114000000	USD
CY2014	nrg	Accrued Expenses And Other Current Liabilities Operating AccruedExpensesAndOtherCurrentLiabilitiesOperating	-26000000	USD
CY2015Q4	nrg	Additional Mutual Lost Revenue Insurance Weekly Maximum AdditionalMutualLostRevenueInsuranceWeeklyMaximum	1980000	USD
CY2013	nrg	Amortization Of Intangibles And Out Of Market Contracts AmortizationOfIntangiblesAndOutOfMarketContracts	49000000	USD
CY2014	nrg	Amortization Of Intangibles And Out Of Market Contracts AmortizationOfIntangiblesAndOutOfMarketContracts	64000000	USD
CY2015	nrg	Amortization Of Intangibles And Out Of Market Contracts AmortizationOfIntangiblesAndOutOfMarketContracts	81000000	USD
CY2013	nrg	Amortization Of Nuclear Fuel AmortizationOfNuclearFuel	36000000	USD
CY2014	nrg	Amortization Of Nuclear Fuel AmortizationOfNuclearFuel	46000000	USD
CY2015	nrg	Amortization Of Nuclear Fuel AmortizationOfNuclearFuel	45000000	USD
CY2015Q4	nrg	Amount Of Credit Exposure To Significant Portion Of All Counterparties AmountOfCreditExposureToSignificantPortionOfAllCounterparties	969000000	USD
CY2015	nrg	Asset Retirement Obligation Accretion Nuclear Decommissioning AssetRetirementObligationAccretionNuclearDecommissioning	16000000	USD
CY2014Q4	nrg	Capital Expenditures CapitalExpenditures	984000000	USD
CY2015Q4	nrg	Capital Expenditures CapitalExpenditures	1267000000	USD
CY2014Q4	nrg	Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months Tax CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonthsTax	0	USD
CY2015Q4	nrg	Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months Tax CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonthsTax	3000000	USD
CY2013	nrg	Changes In Collateral Deposits Supporting Energy Risk Management Activities ChangesInCollateralDepositsSupportingEnergyRiskManagementActivities	-47000000	USD
CY2014	nrg	Changes In Collateral Deposits Supporting Energy Risk Management Activities ChangesInCollateralDepositsSupportingEnergyRiskManagementActivities	146000000	USD
CY2015	nrg	Changes In Collateral Deposits Supporting Energy Risk Management Activities ChangesInCollateralDepositsSupportingEnergyRiskManagementActivities	-381000000	USD
CY2013	nrg	Changes In Derivatives ChangesInDerivatives	164000000	USD
CY2014	nrg	Changes In Derivatives ChangesInDerivatives	-61000000	USD
CY2015	nrg	Changes In Derivatives ChangesInDerivatives	233000000	USD
CY2013	nrg	Changes In Nuclear Decommissioning Trust Liability ChangesInNuclearDecommissioningTrustLiability	15000000	USD
CY2014	nrg	Changes In Nuclear Decommissioning Trust Liability ChangesInNuclearDecommissioningTrustLiability	19000000	USD
CY2015	nrg	Changes In Nuclear Decommissioning Trust Liability ChangesInNuclearDecommissioningTrustLiability	-2000000	USD
CY2015Q4	nrg	Collateral Held Cash And Letters Of Credit CollateralHeldCashAndLettersOfCredit	240000000	USD
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CY2015Q4	nrg	Common Stock Capital Shares Reserved For Employee Stock Purchase Plan CommonStockCapitalSharesReservedForEmployeeStockPurchasePlan	1276913	shares
CY2014Q4	nrg	Common Stock Dividends Proposed Annual Percentage Increase CommonStockDividendsProposedAnnualPercentageIncrease	0.17	pure
CY2015Q4	nrg	Common Stock Dividends Proposed Annual Percentage Increase CommonStockDividendsProposedAnnualPercentageIncrease	0.04	pure
CY2015Q4	nrg	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Pensions And Other Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensionsAndOtherPostretirementBenefits	218000000	USD
CY2014Q4	nrg	Deferred Tax Assets Tax Deferred Expenses Deferred Financing Costs DeferredTaxAssetsTaxDeferredExpensesDeferredFinancingCosts	23000000	USD
CY2013	nrg	Comprehensive Income Loss Net Of Tax Available For Common Stockholders ComprehensiveIncomeLossNetOfTaxAvailableForCommonStockholders	-240000000	USD
CY2014	nrg	Comprehensive Income Loss Net Of Tax Available For Common Stockholders ComprehensiveIncomeLossNetOfTaxAvailableForCommonStockholders	-121000000	USD
CY2015	nrg	Comprehensive Income Loss Net Of Tax Available For Common Stockholders ComprehensiveIncomeLossNetOfTaxAvailableForCommonStockholders	-6382000000	USD
CY2013	nrg	Consent Fees Paid Preferred Stock ConsentFeesPaidPreferredStock	0	USD
CY2014	nrg	Consent Fees Paid Preferred Stock ConsentFeesPaidPreferredStock	5000000	USD
CY2015	nrg	Consent Fees Paid Preferred Stock ConsentFeesPaidPreferredStock	0	USD
CY2013	nrg	Cost Of Services Energy Services Unbilled CostOfServicesEnergyServicesUnbilled	90000000	USD
CY2014	nrg	Cost Of Services Energy Services Unbilled CostOfServicesEnergyServicesUnbilled	86000000	USD
CY2015	nrg	Cost Of Services Energy Services Unbilled CostOfServicesEnergyServicesUnbilled	85000000	USD
CY2015	nrg	Costs Incurred Asset Retirement Obligation Incurred For Acquisition CostsIncurredAssetRetirementObligationIncurredForAcquisition	2000000	USD
CY2015	nrg	Counterparty Credit Risk Exposure Percentage Of Credit Risk Roll Off CounterpartyCreditRiskExposurePercentageOfCreditRiskRollOff	0.97	pure
CY2015	nrg	Counterparty Credit Risk Exposure Percentage Threshold CounterpartyCreditRiskExposurePercentageThreshold	0.10	pure
CY2015Q4	nrg	Credit Derivative Maximum Net Exposure Percentage CreditDerivativeMaximumNetExposurePercentage	1.00	pure
CY2013	nrg	Decrease In Fixed Assets Accrued Grants DecreaseInFixedAssetsAccruedGrants	-681000000	USD
CY2014	nrg	Decrease In Fixed Assets Accrued Grants DecreaseInFixedAssetsAccruedGrants	-711000000	USD
CY2015	nrg	Decrease In Fixed Assets Accrued Grants DecreaseInFixedAssetsAccruedGrants	0	USD
CY2014Q4	nrg	Deferred Tax Assets Differences Between Book And Tax Basis Of Contracts DeferredTaxAssetsDifferencesBetweenBookAndTaxBasisOfContracts	531000000	USD
CY2015Q4	nrg	Deferred Tax Assets Differences Between Book And Tax Basis Of Contracts DeferredTaxAssetsDifferencesBetweenBookAndTaxBasisOfContracts	516000000	USD
CY2014Q4	nrg	Deferred Tax Assets Federal Benefit On State Unrecognized Tax Benefits DeferredTaxAssetsFederalBenefitOnStateUnrecognizedTaxBenefits	17000000	USD
CY2015Q4	nrg	Deferred Tax Assets Federal Benefit On State Unrecognized Tax Benefits DeferredTaxAssetsFederalBenefitOnStateUnrecognizedTaxBenefits	17000000	USD
CY2014Q4	nrg	Deferred Tax Assets Foreign Capital Loss Carryforwards DeferredTaxAssetsForeignCapitalLossCarryforwards	1000000	USD
CY2015Q4	nrg	Deferred Tax Assets Foreign Capital Loss Carryforwards DeferredTaxAssetsForeignCapitalLossCarryforwards	1000000	USD
CY2014Q4	nrg	Deferred Tax Assets Intangibles DeferredTaxAssetsIntangibles	0	USD
CY2015Q4	nrg	Deferred Tax Assets Intangibles DeferredTaxAssetsIntangibles	90000000	USD
CY2014Q4	nrg	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Deferred Compensation Accrued Vacation And Other Reserves DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsDeferredCompensationAccruedVacationAndOtherReserves	266000000	USD
CY2015Q4	nrg	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Deferred Compensation Accrued Vacation And Other Reserves DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsDeferredCompensationAccruedVacationAndOtherReserves	255000000	USD
CY2014Q4	nrg	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Pensions And Other Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensionsAndOtherPostretirementBenefits	157000000	USD
CY2015Q4	nrg	Deferred Tax Assets Tax Deferred Expenses Deferred Financing Costs DeferredTaxAssetsTaxDeferredExpensesDeferredFinancingCosts	6000000	USD
CY2014Q4	nrg	Deferred Tax Liabilities Emissions Allowances DeferredTaxLiabilitiesEmissionsAllowances	25000000	USD
CY2015Q4	nrg	Deferred Tax Liabilities Emissions Allowances DeferredTaxLiabilitiesEmissionsAllowances	31000000	USD
CY2014Q4	nrg	Derivative Asset Fair Value Amount Offset Against Collateral Net Of Derivative Liability Fair Value Amount Offset Against Collateral DerivativeAssetFairValueAmountOffsetAgainstCollateralNetOfDerivativeLiabilityFairValueAmountOffsetAgainstCollateral	368000000	USD
CY2015Q4	nrg	Derivative Asset Fair Value Amount Offset Against Collateral Net Of Derivative Liability Fair Value Amount Offset Against Collateral DerivativeAssetFairValueAmountOffsetAgainstCollateralNetOfDerivativeLiabilityFairValueAmountOffsetAgainstCollateral	164000000	USD
CY2015Q4	nrg	Derivative Asset Fair Value Determined Using Valuation Techniques Percentage DerivativeAssetFairValueDeterminedUsingValuationTechniquesPercentage	0.07	pure
CY2014Q4	nrg	Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset DerivativeAssetFairValueGrossLiabilityNetOfDerivativeLiabilityFairValueGrossAsset	0	USD
CY2015Q4	nrg	Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset DerivativeAssetFairValueGrossLiabilityNetOfDerivativeLiabilityFairValueGrossAsset	0	USD
CY2014Q4	nrg	Derivative Collateral Obligation To Return Cash Net Of Derivative Collateral Right To Reclaim Cash DerivativeCollateralObligationToReturnCashNetOfDerivativeCollateralRightToReclaimCash	-45000000	USD
CY2015Q4	nrg	Derivative Collateral Obligation To Return Cash Net Of Derivative Collateral Right To Reclaim Cash DerivativeCollateralObligationToReturnCashNetOfDerivativeCollateralRightToReclaimCash	158000000	USD
CY2015Q4	nrg	Derivative Liability Fair Value Determined Using Valuation Techniques Percentage DerivativeLiabilityFairValueDeterminedUsingValuationTechniquesPercentage	0.08	pure
CY2015Q4	nrg	Derivative Net Liability Position Collateral Required Adequate Assurance Clauses DerivativeNetLiabilityPositionCollateralRequiredAdequateAssuranceClauses	204000000	USD
CY2015Q4	nrg	Derivative Net Liability Position Collateral Required Contracts With Credit Rating Contingent Feature DerivativeNetLiabilityPositionCollateralRequiredContractsWithCreditRatingContingentFeature	34000000	USD
CY2015Q4	nrg	Derivative Net Liability Position No Counterparty Collateral Call DerivativeNetLiabilityPositionNoCounterpartyCollateralCall	3000000	USD
CY2013	nrg	Derivative Unrealized Gains On Open Positions Related To Trading Activity Net DerivativeUnrealizedGainsOnOpenPositionsRelatedToTradingActivityNet	7000000	USD
CY2014	nrg	Derivative Unrealized Gains On Open Positions Related To Trading Activity Net DerivativeUnrealizedGainsOnOpenPositionsRelatedToTradingActivityNet	45000000	USD
CY2015	nrg	Derivative Unrealized Gains On Open Positions Related To Trading Activity Net DerivativeUnrealizedGainsOnOpenPositionsRelatedToTradingActivityNet	-16000000	USD
CY2014	nrg	Effective Income Tax Rate Reconciliation Reversal Of Uncertain Tax Positions Reserves EffectiveIncomeTaxRateReconciliationReversalOfUncertainTaxPositionsReserves	30000000	USD
CY2013	nrg	Effective Income Tax Rate Reconciliation Reversal Of Uncertain Tax Positions Reserves EffectiveIncomeTaxRateReconciliationReversalOfUncertainTaxPositionsReserves	11000000	USD
CY2015	nrg	Effective Income Tax Rate Reconciliation Reversal Of Uncertain Tax Positions Reserves EffectiveIncomeTaxRateReconciliationReversalOfUncertainTaxPositionsReserves	15000000	USD
CY2013	nrg	Effective Income Tax Rate Reconciliation Tax Expense Attributableto Partnerships EffectiveIncomeTaxRateReconciliationTaxExpenseAttributabletoPartnerships	8000000	USD
CY2014	nrg	Effective Income Tax Rate Reconciliation Tax Expense Attributableto Partnerships EffectiveIncomeTaxRateReconciliationTaxExpenseAttributabletoPartnerships	4000000	USD
CY2015	nrg	Effective Income Tax Rate Reconciliation Tax Expense Attributableto Partnerships EffectiveIncomeTaxRateReconciliationTaxExpenseAttributabletoPartnerships	12000000	USD
CY2015	nrg	Employee Stock Purchase Plan Exercise Price As Percentage Of Fair Value EmployeeStockPurchasePlanExercisePriceAsPercentageOfFairValue	0.85	pure
CY2015	nrg	Employee Stock Purchase Plan Maximum Percentage Of Compensation Eligible EmployeeStockPurchasePlanMaximumPercentageOfCompensationEligible	0.10	pure
CY2015Q4	nrg	Environmental Capital Expenditures Estimated EnvironmentalCapitalExpendituresEstimated	350000000	USD
CY2013	nrg	Equity In Earnings Of Consolidated Subsidiaries EquityInEarningsOfConsolidatedSubsidiaries	0	USD
CY2014	nrg	Equity In Earnings Of Consolidated Subsidiaries EquityInEarningsOfConsolidatedSubsidiaries	0	USD
CY2015	nrg	Equity In Earnings Of Consolidated Subsidiaries EquityInEarningsOfConsolidatedSubsidiaries	0	USD
CY2015	nrg	Estimated Counterparty Credit Risk Exposure To Certain Counterparties EstimatedCounterpartyCreditRiskExposureToCertainCounterparties	3700000000	USD
CY2015	nrg	Estimated Counterparty Credit Risk Exposure To Certain Counterparties Period EstimatedCounterpartyCreditRiskExposureToCertainCounterpartiesPeriod	P5Y
CY2015Q4	nrg	Fair Value Assets Measured On Recurring Basis Valuation Techniques Impact Of Credit Reserve To Fair Value Included In Oci Derivative Contracts FairValueAssetsMeasuredOnRecurringBasisValuationTechniquesImpactOfCreditReserveToFairValueIncludedInOciDerivativeContracts	2000000	USD
CY2015Q4	nrg	Fair Value Assets Measured On Recurring Basis Valuation Techniques Impact Of Credit Reserve To Fair Value Included In Operating Revenues And Cost Of Operations Derivative Contracts FairValueAssetsMeasuredOnRecurringBasisValuationTechniquesImpactOfCreditReserveToFairValueIncludedInOperatingRevenuesAndCostOfOperationsDerivativeContracts	3000000	USD
CY2014Q4	nrg	Fair Valueof Gross Derivative Assets Liabilities Net FairValueofGrossDerivativeAssetsLiabilitiesNet	413000000	USD
CY2015Q4	nrg	Fair Valueof Gross Derivative Assets Liabilities Net FairValueofGrossDerivativeAssetsLiabilitiesNet	6000000	USD
CY2015Q2	nrg	Fees Incurredfor Terminationof Interest Rate Swaps FeesIncurredforTerminationofInterestRateSwaps	17000000	USD
CY2014	nrg	Finite Lived Intangible Assets Acquired During Period FiniteLivedIntangibleAssetsAcquiredDuringPeriod	1541000000	USD
CY2014	nrg	Finite Lived Intangible Assets Other Changes FiniteLivedIntangibleAssetsOtherChanges	-6000000	USD
CY2015	nrg	Finite Lived Intangible Assets Other Changes FiniteLivedIntangibleAssetsOtherChanges	-11000000	USD
CY2014	nrg	Finite Lived Intangible Assets Purchases FiniteLivedIntangibleAssetsPurchases	182000000	USD
CY2015	nrg	Finite Lived Intangible Assets Purchases FiniteLivedIntangibleAssetsPurchases	137000000	USD
CY2014	nrg	Finite Lived Intangible Assets Usage FiniteLivedIntangibleAssetsUsage	34000000	USD
CY2015	nrg	Finite Lived Intangible Assets Usage FiniteLivedIntangibleAssetsUsage	-95000000	USD
CY2014	nrg	Finite Lived Intangible Assets Write Off Of Fully Amortized Intangible Assets FiniteLivedIntangibleAssetsWriteOffOfFullyAmortizedIntangibleAssets	843000000	USD
CY2015	nrg	Finite Lived Intangible Assets Write Off Of Fully Amortized Intangible Assets FiniteLivedIntangibleAssetsWriteOffOfFullyAmortizedIntangibleAssets	-154000000	USD
CY2015Q4	nrg	Forty Four Percent Maximum Assessment FortyFourPercentMaximumAssessment	0.44	pure
CY2014Q4	nrg	Funds Deposited By Counterparties FundsDepositedByCounterparties	72000000	USD
CY2015Q4	nrg	Funds Deposited By Counterparties FundsDepositedByCounterparties	106000000	USD
CY2013	nrg	Gains Losses On Extinguishment Of Debt Non Cash Portion GainsLossesOnExtinguishmentOfDebtNonCashPortion	15000000	USD
CY2014	nrg	Gains Losses On Extinguishment Of Debt Non Cash Portion GainsLossesOnExtinguishmentOfDebtNonCashPortion	-25000000	USD
CY2015	nrg	Gains Losses On Extinguishment Of Debt Non Cash Portion GainsLossesOnExtinguishmentOfDebtNonCashPortion	75000000	USD
CY2013	nrg	Gross Receipts Tax GrossReceiptsTax	88000000	USD
CY2014	nrg	Gross Receipts Tax GrossReceiptsTax	108000000	USD
CY2015	nrg	Gross Receipts Tax GrossReceiptsTax	110000000	USD
CY2015Q4	nrg	Guarantee Maturity Between One To Three Years GuaranteeMaturityBetweenOneToThreeYears	93000000	USD
CY2015Q4	nrg	Guarantee Maturity Between Three To Five Years GuaranteeMaturityBetweenThreeToFiveYears	257000000	USD
CY2015Q4	nrg	Guarantee Maturity Greater Than Five Years GuaranteeMaturityGreaterThanFiveYears	723000000	USD
CY2015Q4	nrg	Guarantee Maturity Less Than One Year GuaranteeMaturityLessThanOneYear	1805000000	USD
CY2014Q4	nrg	Guarantee Obligations Estimated Exposure GuaranteeObligationsEstimatedExposure	3380000000	USD
CY2015Q4	nrg	Guarantee Obligations Estimated Exposure GuaranteeObligationsEstimatedExposure	2878000000	USD
CY2013	nrg	Impairment Charges And Asset Write Downs ImpairmentChargesAndAssetWriteDowns	-558000000	USD
CY2014	nrg	Impairment Charges And Asset Write Downs ImpairmentChargesAndAssetWriteDowns	-97000000	USD
CY2015	nrg	Impairment Charges And Asset Write Downs ImpairmentChargesAndAssetWriteDowns	-5086000000	USD
CY2013	nrg	Income Tax Reconciliation Change In Capital Loss Carryforwards Valuation Allowance IncomeTaxReconciliationChangeInCapitalLossCarryforwardsValuationAllowance	10000000	USD
CY2015	nrg	Income Tax Reconciliation Expiration Capital Losses IncomeTaxReconciliationExpirationCapitalLosses	0	USD
CY2014	nrg	Income Tax Reconciliation Change In Capital Loss Carryforwards Valuation Allowance IncomeTaxReconciliationChangeInCapitalLossCarryforwardsValuationAllowance	0	USD
CY2015	nrg	Income Tax Reconciliation Change In Capital Loss Carryforwards Valuation Allowance IncomeTaxReconciliationChangeInCapitalLossCarryforwardsValuationAllowance	0	USD
CY2013	nrg	Income Tax Reconciliation Expiration Capital Losses IncomeTaxReconciliationExpirationCapitalLosses	10000000	USD
CY2014	nrg	Income Tax Reconciliation Expiration Capital Losses IncomeTaxReconciliationExpirationCapitalLosses	0	USD
CY2013	nrg	Income Tax Reconciliation Impact Of Non Taxible Equity Earning IncomeTaxReconciliationImpactOfNonTaxibleEquityEarning	-14000000	USD
CY2014	nrg	Income Tax Reconciliation Impact Of Non Taxible Equity Earning IncomeTaxReconciliationImpactOfNonTaxibleEquityEarning	-11000000	USD
CY2015	nrg	Income Tax Reconciliation Impact Of Non Taxible Equity Earning IncomeTaxReconciliationImpactOfNonTaxibleEquityEarning	-10000000	USD
CY2015	nrg	Income Taxes Threshold Percentage IncomeTaxesThresholdPercentage	0.5	pure
CY2013	nrg	Increase Decrease In Notes Receivable IncreaseDecreaseInNotesReceivable	-11000000	USD
CY2014	nrg	Increase Decrease In Notes Receivable IncreaseDecreaseInNotesReceivable	25000000	USD
CY2015	nrg	Increase Decrease In Notes Receivable IncreaseDecreaseInNotesReceivable	18000000	USD
CY2013	nrg	Increase Decrease In Restricted Cash To Support Equity Requirements For Us Doe Funded Projects IncreaseDecreaseInRestrictedCashToSupportEquityRequirementsForUSDoeFundedProjects	26000000	USD
CY2014	nrg	Increase Decrease In Restricted Cash To Support Equity Requirements For Us Doe Funded Projects IncreaseDecreaseInRestrictedCashToSupportEquityRequirementsForUSDoeFundedProjects	206000000	USD
CY2015	nrg	Increase Decrease In Restricted Cash To Support Equity Requirements For Us Doe Funded Projects IncreaseDecreaseInRestrictedCashToSupportEquityRequirementsForUSDoeFundedProjects	-35000000	USD
CY2015Q4	nrg	Industry Mutual Insurance Company Multiplier IndustryMutualInsuranceCompanyMultiplier	10	pure
CY2013	nrg	Inter Segment Sales InterSegmentSales	2308000000	USD
CY2014	nrg	Inter Segment Sales InterSegmentSales	1949000000	USD
CY2015	nrg	Inter Segment Sales InterSegmentSales	1218000000	USD
CY2013	nrg	Intercompany Loans To Receipts From Subsidiaries IntercompanyLoansToReceiptsFromSubsidiaries	0	USD
CY2014	nrg	Intercompany Loans To Receipts From Subsidiaries IntercompanyLoansToReceiptsFromSubsidiaries	0	USD
CY2015	nrg	Intercompany Loans To Receipts From Subsidiaries IntercompanyLoansToReceiptsFromSubsidiaries	0	USD
CY2013	nrg	Investments In Proceeds From Sales Of Unconsolidated Affiliates InvestmentsInProceedsFromSalesOfUnconsolidatedAffiliates	0	USD
CY2014	nrg	Investments In Proceeds From Sales Of Unconsolidated Affiliates InvestmentsInProceedsFromSalesOfUnconsolidatedAffiliates	-103000000	USD
CY2015	nrg	Investments In Proceeds From Sales Of Unconsolidated Affiliates InvestmentsInProceedsFromSalesOfUnconsolidatedAffiliates	-395000000	USD
CY2015Q4	nrg	Longterm Debtexcluding Unamortized Discount Premiumnet LongtermDebtexcludingUnamortizedDiscountPremiumnet	19496000000	USD
CY2014	nrg	Losson Extinguishmentof Preferred Stock LossonExtinguishmentofPreferredStock	42000000	USD
CY2015	nrg	Maximum Remaining Termunder Individual Purchased Power Contract MaximumRemainingTermunderIndividualPurchasedPowerContract	P5Y
CY2015Q4	nrg	Mutual Lost Revenue Insurance Maximum Weekly Recovery MutualLostRevenueInsuranceMaximumWeeklyRecovery	3000000	USD
CY2015Q4	nrg	Mutual Property Insurance Additional Blanket Policy Property Coverage MutualPropertyInsuranceAdditionalBlanketPolicyPropertyCoverage	1000000000	USD
CY2015Q4	nrg	Mutual Property Insurance Individual Maximum Property Coverage Limit MutualPropertyInsuranceIndividualMaximumPropertyCoverageLimit	1500000000	USD
CY2015Q4	nrg	Net Credit Exposure NetCreditExposure	733000000	USD
CY2014Q4	nrg	Net Deferred Tax Asset NetDeferredTaxAsset	1500000000	USD
CY2015Q4	nrg	Net Deferred Tax Asset NetDeferredTaxAsset	148000000	USD
CY2014	nrg	Noncashadjustmentforissuanceofconvertibledebt Noncashadjustmentforissuanceofconvertibledebt	23000000	USD
CY2015	nrg	Noncashadjustmentforissuanceofconvertibledebt Noncashadjustmentforissuanceofconvertibledebt	23000000	USD
CY2015	nrg	Noncontrolling Interest Contributionsfrom Noncontrolling Interest Holders NoncontrollingInterestContributionsfromNoncontrollingInterestHolders	234000000	USD
CY2014Q4	nrg	Nuclear Decommissioning Trust Fund Liability Noncurrent NuclearDecommissioningTrustFundLiabilityNoncurrent	333000000	USD
CY2015Q4	nrg	Nuclear Decommissioning Trust Fund Liability Noncurrent NuclearDecommissioningTrustFundLiabilityNoncurrent	283000000	USD
CY2015Q4	nrg	Nuclear Insurance Financial Protection Pool Maximum Annual Assessment NuclearInsuranceFinancialProtectionPoolMaximumAnnualAssessment	19000000	USD
CY2015Q4	nrg	Nuclear Insurance Financial Protection Pool Maximum Assessment NuclearInsuranceFinancialProtectionPoolMaximumAssessment	127000000	USD
CY2015Q4	nrg	Nuclear Insurance Financial Protection Pool Maximum Assessment Adminstrative Fee Asa Percent NuclearInsuranceFinancialProtectionPoolMaximumAssessmentAdminstrativeFeeAsaPercent	0.05	pure
CY2015Q4	nrg	Nuclear Insurance Financial Protection Pool Nuclear Operator Maximum Annual Assessment NuclearInsuranceFinancialProtectionPoolNuclearOperatorMaximumAnnualAssessment	8000000	USD
CY2015Q4	nrg	Nuclear Insurance Financial Protection Pool Nuclear Operator Total Assessment NuclearInsuranceFinancialProtectionPoolNuclearOperatorTotalAssessment	112000000	USD
CY2015Q4	nrg	Nuclear Insurance Financial Protection Pool Value NuclearInsuranceFinancialProtectionPoolValue	13500000000	USD
CY2015Q4	nrg	Nuclear Insurance Per Incident Coverage Limit NuclearInsurancePerIncidentCoverageLimit	13500000000	USD
CY2015Q4	nrg	Nuclear Insurance Requirement Per Site NuclearInsuranceRequirementPerSite	375000000	USD
CY2012Q3	nrg	Number Of Pjm Transmission Owners Who Filed Motion NumberOfPjmTransmissionOwnersWhoFiledMotion	3
CY2010Q2	nrg	Number Of Significant Orders Issued By Authority NumberOfSignificantOrdersIssuedByAuthority	2	orders
CY2015	nrg	Number Of Years Board Of Directors Of Industry Mutual Insurance Company Can Adjust Policy After Policy Expires NumberOfYearsBoardOfDirectorsOfIndustryMutualInsuranceCompanyCanAdjustPolicyAfterPolicyExpires	P6Y
CY2015	nrg	Payments To Settle Acquired Derivatives That Include Financing Elements PaymentsToSettleAcquiredDerivativesThatIncludeFinancingElements	-196000000	USD
CY2015	nrg	Period Beyondwhich Comapny Can Not Predict Holdingof Collateral PeriodBeyondwhichComapnyCanNotPredictHoldingofCollateral	P12M
CY2013	nrg	Operating Cost And Expense Excluding Depreciation Depletion And Amortization OperatingCostAndExpenseExcludingDepreciationDepletionAndAmortization	9025000000	USD
CY2014	nrg	Operating Cost And Expense Excluding Depreciation Depletion And Amortization OperatingCostAndExpenseExcludingDepreciationDepletionAndAmortization	12821000000	USD
CY2015	nrg	Operating Cost And Expense Excluding Depreciation Depletion And Amortization OperatingCostAndExpenseExcludingDepreciationDepletionAndAmortization	11975000000	USD
CY2015Q4	nrg	Other Assets Noncurrent Emission Allowances OtherAssetsNoncurrentEmissionAllowances	22000000	USD
CY2015	nrg	Other Comprehensive Income Loss Including Oc Ifor Nci OtherComprehensiveIncomeLossIncludingOCIforNCI	-3000000	USD
CY2015	nrg	Payment Of Intercompany Dividends PaymentOfIntercompanyDividends	201000000	USD
CY2013	nrg	Payments To Settle Acquired Derivatives That Include Financing Elements PaymentsToSettleAcquiredDerivativesThatIncludeFinancingElements	-267000000	USD
CY2014	nrg	Payments To Settle Acquired Derivatives That Include Financing Elements PaymentsToSettleAcquiredDerivativesThatIncludeFinancingElements	-9000000	USD
CY2015	nrg	Periodofretrospectivepremiumadjustments Periodofretrospectivepremiumadjustments	P24M
CY2015Q4	nrg	Power Generation Capacity Megawatts PowerGenerationCapacityMegawatts	49287
CY2015Q4	nrg	Preferred Stock Instrument Interest Rate Stated Percentage PreferredStockInstrumentInterestRateStatedPercentage	2.822	pure
CY2014Q4	nrg	Preferred Stock Instrument Interest Rate Stated Percentage PreferredStockInstrumentInterestRateStatedPercentage	3.625	pure
CY2014Q4	nrg	Prepaid Expense And Other Assets Current Less Accounts Receivable Affiliate PrepaidExpenseAndOtherAssetsCurrentLessAccountsReceivableAffiliate	438000000	USD
CY2015Q4	nrg	Prepaid Expense And Other Assets Current Less Accounts Receivable Affiliate PrepaidExpenseAndOtherAssetsCurrentLessAccountsReceivableAffiliate	438000000	USD
CY2013	nrg	Proceeds From Payments To Intercompany Loans ProceedsFromPaymentsToIntercompanyLoans	0	USD
CY2014	nrg	Proceeds From Payments To Intercompany Loans ProceedsFromPaymentsToIntercompanyLoans	0	USD
CY2015	nrg	Proceeds From Payments To Intercompany Loans ProceedsFromPaymentsToIntercompanyLoans	0	USD
CY2013	nrg	Proceeds From Renewable Energy Grants ProceedsFromRenewableEnergyGrants	55000000	USD
CY2014	nrg	Proceeds From Renewable Energy Grants ProceedsFromRenewableEnergyGrants	916000000	USD
CY2015	nrg	Proceeds From Renewable Energy Grants ProceedsFromRenewableEnergyGrants	82000000	USD
CY2014Q4	nrg	Property Plant And Equipment In Service PropertyPlantAndEquipmentInService	29487000000	USD
CY2015Q4	nrg	Property Plant And Equipment In Service PropertyPlantAndEquipmentInService	24909000000	USD
CY2014	nrg	Redeemable Noncontrolling Interest Cash Contributionsfrom Noncontrolling Interest Holders RedeemableNoncontrollingInterestCashContributionsfromNoncontrollingInterestHolders	36000000	USD
CY2015	nrg	Redeemable Noncontrolling Interest Cash Contributionsfrom Noncontrolling Interest Holders RedeemableNoncontrollingInterestCashContributionsfromNoncontrollingInterestHolders	27000000	USD
CY2014Q4	nrg	Redeemable Preferred Stock Fair Value RedeemablePreferredStockFairValue	291000000	USD
CY2011Q4	nrg	Regulatory Charges Owed By Third Party RegulatoryChargesOwedByThirdParty	22000000	USD
CY2012Q3	nrg	Regulatory Charges Settled By Third Party RegulatoryChargesSettledByThirdParty	24000000	USD
CY2012Q3	nrg	Regulatory Charges Settled By Third Party Additional RegulatoryChargesSettledByThirdPartyAdditional	1000000	USD
CY2013	nrg	Revenues From Resale Of Purchased Power RevenuesFromResaleOfPurchasedPower	166000000	USD
CY2014	nrg	Revenues From Resale Of Purchased Power RevenuesFromResaleOfPurchasedPower	387000000	USD
CY2015	nrg	Revenues From Resale Of Purchased Power RevenuesFromResaleOfPurchasedPower	165000000	USD
CY2013	nrg	Reversal Of Previously Unrecognized Unrealized Gain Loss Acquired As Part Of Acquisition Trading Activity ReversalOfPreviouslyUnrecognizedUnrealizedGainLossAcquiredAsPartOfAcquisitionTradingActivity	0	USD
CY2014	nrg	Reversal Of Previously Unrecognized Unrealized Gain Loss Acquired As Part Of Acquisition Trading Activity ReversalOfPreviouslyUnrecognizedUnrealizedGainLossAcquiredAsPartOfAcquisitionTradingActivity	-32000000	USD
CY2015	nrg	Reversal Of Previously Unrecognized Unrealized Gain Loss Acquired As Part Of Acquisition Trading Activity ReversalOfPreviouslyUnrecognizedUnrealizedGainLossAcquiredAsPartOfAcquisitionTradingActivity	-14000000	USD
CY2013	nrg	Reversal Previously Unrecognized Unrealized Gains Losses Acquired As Part Of Acquisition Economic Hedges ReversalPreviouslyUnrecognizedUnrealizedGainsLossesAcquiredAsPartOfAcquisitionEconomicHedges	357000000	USD
CY2014	nrg	Reversal Previously Unrecognized Unrealized Gains Losses Acquired As Part Of Acquisition Economic Hedges ReversalPreviouslyUnrecognizedUnrealizedGainsLossesAcquiredAsPartOfAcquisitionEconomicHedges	333000000	USD
CY2015	nrg	Reversal Previously Unrecognized Unrealized Gains Losses Acquired As Part Of Acquisition Economic Hedges ReversalPreviouslyUnrecognizedUnrealizedGainsLossesAcquiredAsPartOfAcquisitionEconomicHedges	106000000	USD
CY2013	nrg	Reversal Previously Unrecognized Unrealized Gains Losses Settled Positions Economic Hedges ReversalPreviouslyUnrecognizedUnrealizedGainsLossesSettledPositionsEconomicHedges	105000000	USD
CY2014	nrg	Reversal Previously Unrecognized Unrealized Gains Losses Settled Positions Economic Hedges ReversalPreviouslyUnrecognizedUnrealizedGainsLossesSettledPositionsEconomicHedges	15000000	USD
CY2015	nrg	Reversal Previously Unrecognized Unrealized Gains Losses Settled Positions Economic Hedges ReversalPreviouslyUnrecognizedUnrealizedGainsLossesSettledPositionsEconomicHedges	275000000	USD
CY2013	nrg	Reversal Previously Unrecognized Unrealized Gains Losses Settled Positions Trading Activity ReversalPreviouslyUnrecognizedUnrealizedGainsLossesSettledPositionsTradingActivity	50000000	USD
CY2014	nrg	Reversal Previously Unrecognized Unrealized Gains Losses Settled Positions Trading Activity ReversalPreviouslyUnrecognizedUnrealizedGainsLossesSettledPositionsTradingActivity	-1000000	USD
CY2015	nrg	Reversal Previously Unrecognized Unrealized Gains Losses Settled Positions Trading Activity ReversalPreviouslyUnrecognizedUnrealizedGainsLossesSettledPositionsTradingActivity	46000000	USD
CY2015	nrg	Share Based Compensation Arrangement By Share Based Payment Award Number Of Types Of Awards ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfTypesOfAwards	5	TypesOfAwards
CY2014Q4	nrg	Temporary Equity Liquidation Value TemporaryEquityLiquidationValue	250	USD
CY2014	nrg	Unrealized Gain Loss On Derivatives Mark To Market Economic Hedging Activities UnrealizedGainLossOnDerivativesMarkToMarketEconomicHedgingActivities	13000000	USD
CY2015Q4	nrg	Temporary Equity Liquidation Value TemporaryEquityLiquidationValue	250	USD
CY2013	nrg	Unrealized Gain Loss On Derivatives Mark To Market Economic Hedging Activities UnrealizedGainLossOnDerivativesMarkToMarketEconomicHedgingActivities	-285000000	USD
CY2015	nrg	Unrealized Gain Loss On Derivatives Mark To Market Economic Hedging Activities UnrealizedGainLossOnDerivativesMarkToMarketEconomicHedgingActivities	-372000000	USD
CY2013	nrg	Unrealized Gain Loss On Derivatives Mark To Market Trading Activites UnrealizedGainLossOnDerivativesMarkToMarketTradingActivites	-43000000	USD
CY2014	nrg	Unrealized Gain Loss On Derivatives Mark To Market Trading Activites UnrealizedGainLossOnDerivativesMarkToMarketTradingActivites	14000000	USD
CY2015	nrg	Unrealized Gain Loss On Derivatives Mark To Market Trading Activites UnrealizedGainLossOnDerivativesMarkToMarketTradingActivites	-76000000	USD
CY2015Q4	nrg	Variable Interest Entity Consolidated Carrying Amount Current Assets VariableInterestEntityConsolidatedCarryingAmountCurrentAssets	84000000	USD
CY2015Q4	nrg	Variable Interest Entity Consolidated Carrying Amount Current Liabilities VariableInterestEntityConsolidatedCarryingAmountCurrentLiabilities	56000000	USD
CY2015Q4	nrg	Variable Interest Entity Consolidated Carrying Amount Longterm Debt VariableInterestEntityConsolidatedCarryingAmountLongtermDebt	366000000	USD
CY2015Q4	nrg	Variable Interest Entity Consolidated Carrying Amount Net Property Plantand Equipment VariableInterestEntityConsolidatedCarryingAmountNetPropertyPlantandEquipment	1807000000	USD
CY2015Q4	nrg	Variable Interest Entity Consolidated Carrying Amount Noncontrolling Interest VariableInterestEntityConsolidatedCarryingAmountNoncontrollingInterest	493000000	USD
CY2015Q4	nrg	Variable Interest Entity Consolidated Carrying Amount Other Longterm Assets VariableInterestEntityConsolidatedCarryingAmountOtherLongtermAssets	863000000	USD
CY2015Q4	nrg	Variable Interest Entity Consolidated Carrying Amount Other Longterm Liabilities VariableInterestEntityConsolidatedCarryingAmountOtherLongtermLiabilities	179000000	USD
CY2015Q4	nrg	Working Capital Facility Amount Drawn WorkingCapitalFacilityAmountDrawn	14000000	USD
CY2014Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	1060000000	USD
CY2015Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	869000000	USD
CY2014Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	1322000000	USD
CY2015Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	1157000000	USD
CY2015Q4	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	5000000	USD
CY2014Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	7890000000	USD
CY2015Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	6804000000	USD
CY2012Q4	us-gaap	Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Net Of Tax AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax	-31000000	USD
CY2013Q4	us-gaap	Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Net Of Tax AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax	-23000000	USD
CY2014Q4	us-gaap	Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Net Of Tax AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax	-68000000	USD
CY2015Q4	us-gaap	Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Net Of Tax AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax	-101000000	USD
CY2013Q4	us-gaap	Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax	15000000	USD
CY2014Q4	us-gaap	Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax	1000000	USD
CY2015Q4	us-gaap	Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax	-10000000	USD
CY2014Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-174000000	USD
CY2015Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-173000000	USD
CY2014Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	8327000000	USD
CY2015Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	8296000000	USD
CY2013	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	36000000	USD
CY2014	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	45000000	USD
CY2015	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	24000000	USD
CY2013	us-gaap	Advertising Expense AdvertisingExpense	69000000	USD
CY2014	us-gaap	Advertising Expense AdvertisingExpense	87000000	USD
CY2015	us-gaap	Advertising Expense AdvertisingExpense	135000000	USD
CY2013	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	40000000	USD
CY2014	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	42000000	USD
CY2015	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	41000000	USD
CY2014Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	23000000	USD
CY2015Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	21000000	USD
CY2013	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	-33000000	USD
CY2014	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	-12000000	USD
CY2015	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	-11000000	USD
CY2013	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	279000000	USD
CY2014	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	268000000	USD
CY2015	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	277000000	USD
CY2015Q4	us-gaap	Amount Of Restricted Net Assets For Consolidated And Unconsolidated Subsidiaries AmountOfRestrictedNetAssetsForConsolidatedAndUnconsolidatedSubsidiaries	5600000000	USD
CY2013	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	25000000	shares
CY2014	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	17000000	shares
CY2015	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	22000000	shares
CY2013	us-gaap	Asset Impairment Charges AssetImpairmentCharges	459000000	USD
CY2014	us-gaap	Asset Impairment Charges AssetImpairmentCharges	97000000	USD
CY2015	us-gaap	Asset Impairment Charges AssetImpairmentCharges	5030000000	USD
CY2014Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	763000000	USD
CY2015Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	945000000	USD
CY2015	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	35000000	USD
CY2015	us-gaap	Asset Retirement Obligation Liabilities Settled AssetRetirementObligationLiabilitiesSettled	-11000000	USD
CY2015	us-gaap	Asset Retirement Obligation Revision Of Estimate AssetRetirementObligationRevisionOfEstimate	122000000	USD
CY2014Q4	us-gaap	Assets Assets	40466000000	USD
CY2015Q4	us-gaap	Assets Assets	32882000000	USD
CY2014Q4	us-gaap	Assets Current AssetsCurrent	8408000000	USD
CY2015Q4	us-gaap	Assets Current AssetsCurrent	7391000000	USD
CY2014Q4	us-gaap	Assets Noncurrent AssetsNoncurrent	9691000000	USD
CY2015Q4	us-gaap	Assets Noncurrent AssetsNoncurrent	6759000000	USD
CY2013	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	25000000	USD
CY2014	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	29000000	USD
CY2015	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	21000000	USD
CY2013	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	8000000	USD
CY2014	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	8000000	USD
CY2015	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	14000000	USD
CY2014	us-gaap	Available For Sale Securities Gross Unrealized Gains AvailableForSaleSecuritiesGrossUnrealizedGains	218000000	USD
CY2015	us-gaap	Available For Sale Securities Gross Unrealized Gains AvailableForSaleSecuritiesGrossUnrealizedGains	202000000	USD
CY2014	us-gaap	Available For Sale Securities Gross Unrealized Loss AvailableForSaleSecuritiesGrossUnrealizedLoss	2000000	USD
CY2015	us-gaap	Available For Sale Securities Gross Unrealized Loss AvailableForSaleSecuritiesGrossUnrealizedLoss	3000000	USD
CY2014Q4	us-gaap	Business Acquisition Purchase Price Allocation Goodwill Expected Tax Deductible Amount BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount	831000000	USD
CY2015Q4	us-gaap	Business Acquisition Purchase Price Allocation Goodwill Expected Tax Deductible Amount BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount	620000000	USD
CY2013	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	128000000	USD
CY2014	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	84000000	USD
CY2015	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	10000000	USD
CY2013	us-gaap	Business Combination Integration Related Costs BusinessCombinationIntegrationRelatedCosts	128000000	USD
CY2014	us-gaap	Business Combination Integration Related Costs BusinessCombinationIntegrationRelatedCosts	84000000	USD
CY2015	us-gaap	Business Combination Integration Related Costs BusinessCombinationIntegrationRelatedCosts	10000000	USD
CY2013	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	405000000	USD
CY2014	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	87000000	USD
CY2015	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	-24000000	USD
CY2012Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	2087000000	USD
CY2013Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	2254000000	USD
CY2014Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	2116000000	USD
CY2015Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	1518000000	USD
CY2013	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	167000000	USD
CY2014	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	-138000000	USD
CY2015	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	-598000000	USD
CY2015	us-gaap	Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths	-18000000	USD
CY2015Q4	us-gaap	Common Stock Capital Shares Reserved For Future Issuance CommonStockCapitalSharesReservedForFutureIssuance	33979967	shares
CY2012Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.12
CY2013Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.00090
CY2013Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.00120
CY2013Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.00120
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0

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CY2014

nrg

Comprehensive Income Loss Net Of Tax Available For Common Stockholders

ComprehensiveIncomeLossNetOfTaxAvailableForCommonStockholders

-121000000

USD

CY2015

nrg

Comprehensive Income Loss Net Of Tax Available For Common Stockholders

ComprehensiveIncomeLossNetOfTaxAvailableForCommonStockholders

-6382000000

USD

CY2013

nrg

Consent Fees Paid Preferred Stock

ConsentFeesPaidPreferredStock

0

USD

CY2014

nrg

Consent Fees Paid Preferred Stock

ConsentFeesPaidPreferredStock

5000000

USD

CY2015

nrg

Consent Fees Paid Preferred Stock

ConsentFeesPaidPreferredStock

0

USD

CY2013

nrg

Cost Of Services Energy Services Unbilled

CostOfServicesEnergyServicesUnbilled

90000000

USD

CY2014

nrg

Cost Of Services Energy Services Unbilled

CostOfServicesEnergyServicesUnbilled

86000000

USD

CY2015

nrg

Cost Of Services Energy Services Unbilled

CostOfServicesEnergyServicesUnbilled

85000000

USD

CY2015

nrg

Costs Incurred Asset Retirement Obligation Incurred For Acquisition

CostsIncurredAssetRetirementObligationIncurredForAcquisition

2000000

USD

CY2015

nrg

Counterparty Credit Risk Exposure Percentage Of Credit Risk Roll Off

CounterpartyCreditRiskExposurePercentageOfCreditRiskRollOff

0.97

pure

CY2015

nrg

Counterparty Credit Risk Exposure Percentage Threshold

CounterpartyCreditRiskExposurePercentageThreshold

0.10

pure

CY2015Q4

nrg

Credit Derivative Maximum Net Exposure Percentage

CreditDerivativeMaximumNetExposurePercentage

1.00

pure

CY2013

nrg

Decrease In Fixed Assets Accrued Grants

DecreaseInFixedAssetsAccruedGrants

-681000000

USD

CY2014

nrg

Decrease In Fixed Assets Accrued Grants

DecreaseInFixedAssetsAccruedGrants

-711000000

USD

CY2015

nrg

Decrease In Fixed Assets Accrued Grants

DecreaseInFixedAssetsAccruedGrants

0

USD

CY2014Q4

nrg

Deferred Tax Assets Differences Between Book And Tax Basis Of Contracts

DeferredTaxAssetsDifferencesBetweenBookAndTaxBasisOfContracts

531000000

USD

CY2015Q4

nrg

Deferred Tax Assets Differences Between Book And Tax Basis Of Contracts

DeferredTaxAssetsDifferencesBetweenBookAndTaxBasisOfContracts

516000000

USD

CY2014Q4

nrg

Deferred Tax Assets Federal Benefit On State Unrecognized Tax Benefits

DeferredTaxAssetsFederalBenefitOnStateUnrecognizedTaxBenefits

17000000

USD

CY2015Q4

nrg

Deferred Tax Assets Federal Benefit On State Unrecognized Tax Benefits

DeferredTaxAssetsFederalBenefitOnStateUnrecognizedTaxBenefits

17000000

USD

CY2014Q4

nrg

Deferred Tax Assets Foreign Capital Loss Carryforwards

DeferredTaxAssetsForeignCapitalLossCarryforwards

1000000

USD

CY2015Q4

nrg

Deferred Tax Assets Foreign Capital Loss Carryforwards

DeferredTaxAssetsForeignCapitalLossCarryforwards

1000000

USD

CY2014Q4

nrg

Deferred Tax Assets Intangibles

DeferredTaxAssetsIntangibles

0

USD

CY2015Q4

nrg

Deferred Tax Assets Intangibles

DeferredTaxAssetsIntangibles

90000000

USD

CY2014Q4

nrg

Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Deferred Compensation Accrued Vacation And Other Reserves

DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsDeferredCompensationAccruedVacationAndOtherReserves

266000000

USD

CY2015Q4

nrg

Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Deferred Compensation Accrued Vacation And Other Reserves

DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsDeferredCompensationAccruedVacationAndOtherReserves

255000000

USD

CY2014Q4

nrg

Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Pensions And Other Postretirement Benefits

DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensionsAndOtherPostretirementBenefits

157000000

USD

CY2015Q4

nrg

Deferred Tax Assets Tax Deferred Expenses Deferred Financing Costs

DeferredTaxAssetsTaxDeferredExpensesDeferredFinancingCosts

6000000

USD

CY2014Q4

nrg

Deferred Tax Liabilities Emissions Allowances

DeferredTaxLiabilitiesEmissionsAllowances

25000000

USD

CY2015Q4

nrg

Deferred Tax Liabilities Emissions Allowances

DeferredTaxLiabilitiesEmissionsAllowances

31000000

USD

CY2014Q4

nrg

Derivative Asset Fair Value Amount Offset Against Collateral Net Of Derivative Liability Fair Value Amount Offset Against Collateral

DerivativeAssetFairValueAmountOffsetAgainstCollateralNetOfDerivativeLiabilityFairValueAmountOffsetAgainstCollateral

368000000

USD

CY2015Q4

nrg

Derivative Asset Fair Value Amount Offset Against Collateral Net Of Derivative Liability Fair Value Amount Offset Against Collateral

DerivativeAssetFairValueAmountOffsetAgainstCollateralNetOfDerivativeLiabilityFairValueAmountOffsetAgainstCollateral

164000000

USD

CY2015Q4

nrg

Derivative Asset Fair Value Determined Using Valuation Techniques Percentage

DerivativeAssetFairValueDeterminedUsingValuationTechniquesPercentage

0.07

pure

CY2014Q4

nrg

Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset

DerivativeAssetFairValueGrossLiabilityNetOfDerivativeLiabilityFairValueGrossAsset

0

USD

CY2015Q4

nrg

Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset

DerivativeAssetFairValueGrossLiabilityNetOfDerivativeLiabilityFairValueGrossAsset

0

USD

CY2014Q4

nrg

Derivative Collateral Obligation To Return Cash Net Of Derivative Collateral Right To Reclaim Cash

DerivativeCollateralObligationToReturnCashNetOfDerivativeCollateralRightToReclaimCash

-45000000

USD

CY2015Q4

nrg

Derivative Collateral Obligation To Return Cash Net Of Derivative Collateral Right To Reclaim Cash

DerivativeCollateralObligationToReturnCashNetOfDerivativeCollateralRightToReclaimCash

158000000

USD

CY2015Q4

nrg

Derivative Liability Fair Value Determined Using Valuation Techniques Percentage

DerivativeLiabilityFairValueDeterminedUsingValuationTechniquesPercentage

0.08

pure

CY2015Q4

nrg

Derivative Net Liability Position Collateral Required Adequate Assurance Clauses

DerivativeNetLiabilityPositionCollateralRequiredAdequateAssuranceClauses

204000000

USD

CY2015Q4

nrg

Derivative Net Liability Position Collateral Required Contracts With Credit Rating Contingent Feature

DerivativeNetLiabilityPositionCollateralRequiredContractsWithCreditRatingContingentFeature

34000000

USD

CY2015Q4

nrg

Derivative Net Liability Position No Counterparty Collateral Call

DerivativeNetLiabilityPositionNoCounterpartyCollateralCall

3000000

USD

CY2013

nrg

Derivative Unrealized Gains On Open Positions Related To Trading Activity Net

DerivativeUnrealizedGainsOnOpenPositionsRelatedToTradingActivityNet

7000000

USD

CY2014

nrg

Derivative Unrealized Gains On Open Positions Related To Trading Activity Net

DerivativeUnrealizedGainsOnOpenPositionsRelatedToTradingActivityNet

45000000

USD

CY2015

nrg

Derivative Unrealized Gains On Open Positions Related To Trading Activity Net

DerivativeUnrealizedGainsOnOpenPositionsRelatedToTradingActivityNet

-16000000

USD

CY2014

nrg

Effective Income Tax Rate Reconciliation Reversal Of Uncertain Tax Positions Reserves

EffectiveIncomeTaxRateReconciliationReversalOfUncertainTaxPositionsReserves

30000000

USD

CY2013

nrg

Effective Income Tax Rate Reconciliation Reversal Of Uncertain Tax Positions Reserves

EffectiveIncomeTaxRateReconciliationReversalOfUncertainTaxPositionsReserves

11000000

USD

CY2015

nrg

Effective Income Tax Rate Reconciliation Reversal Of Uncertain Tax Positions Reserves

EffectiveIncomeTaxRateReconciliationReversalOfUncertainTaxPositionsReserves

15000000

USD

CY2013

nrg

Effective Income Tax Rate Reconciliation Tax Expense Attributableto Partnerships

EffectiveIncomeTaxRateReconciliationTaxExpenseAttributabletoPartnerships

8000000

USD

CY2014

nrg

Effective Income Tax Rate Reconciliation Tax Expense Attributableto Partnerships

EffectiveIncomeTaxRateReconciliationTaxExpenseAttributabletoPartnerships

4000000

USD

CY2015

nrg

Effective Income Tax Rate Reconciliation Tax Expense Attributableto Partnerships

EffectiveIncomeTaxRateReconciliationTaxExpenseAttributabletoPartnerships

12000000

USD

CY2015

nrg

Employee Stock Purchase Plan Exercise Price As Percentage Of Fair Value

EmployeeStockPurchasePlanExercisePriceAsPercentageOfFairValue

0.85

pure

CY2015

nrg

Employee Stock Purchase Plan Maximum Percentage Of Compensation Eligible

EmployeeStockPurchasePlanMaximumPercentageOfCompensationEligible

0.10

pure

CY2015Q4

nrg

Environmental Capital Expenditures Estimated

EnvironmentalCapitalExpendituresEstimated

350000000

USD

CY2013

nrg

Equity In Earnings Of Consolidated Subsidiaries

EquityInEarningsOfConsolidatedSubsidiaries

0

USD

CY2014

nrg

Equity In Earnings Of Consolidated Subsidiaries

EquityInEarningsOfConsolidatedSubsidiaries

0

USD

CY2015

nrg

Equity In Earnings Of Consolidated Subsidiaries

EquityInEarningsOfConsolidatedSubsidiaries

0

USD

CY2015

nrg

Estimated Counterparty Credit Risk Exposure To Certain Counterparties

EstimatedCounterpartyCreditRiskExposureToCertainCounterparties

3700000000

USD

CY2015

nrg

Estimated Counterparty Credit Risk Exposure To Certain Counterparties Period

EstimatedCounterpartyCreditRiskExposureToCertainCounterpartiesPeriod

P5Y

CY2015Q4

nrg

Fair Value Assets Measured On Recurring Basis Valuation Techniques Impact Of Credit Reserve To Fair Value Included In Oci Derivative Contracts

FairValueAssetsMeasuredOnRecurringBasisValuationTechniquesImpactOfCreditReserveToFairValueIncludedInOciDerivativeContracts

2000000

USD

CY2015Q4

nrg

Fair Value Assets Measured On Recurring Basis Valuation Techniques Impact Of Credit Reserve To Fair Value Included In Operating Revenues And Cost Of Operations Derivative Contracts

FairValueAssetsMeasuredOnRecurringBasisValuationTechniquesImpactOfCreditReserveToFairValueIncludedInOperatingRevenuesAndCostOfOperationsDerivativeContracts

3000000

USD

CY2014Q4

nrg

Fair Valueof Gross Derivative Assets Liabilities Net

FairValueofGrossDerivativeAssetsLiabilitiesNet

413000000

USD

CY2015Q4

nrg

Fair Valueof Gross Derivative Assets Liabilities Net

FairValueofGrossDerivativeAssetsLiabilitiesNet

6000000

USD

CY2015Q2

nrg

Fees Incurredfor Terminationof Interest Rate Swaps

FeesIncurredforTerminationofInterestRateSwaps

17000000

USD

CY2014

nrg

Finite Lived Intangible Assets Acquired During Period

FiniteLivedIntangibleAssetsAcquiredDuringPeriod

1541000000

USD

CY2014

nrg

Finite Lived Intangible Assets Other Changes

FiniteLivedIntangibleAssetsOtherChanges

-6000000

USD

CY2015

nrg

Finite Lived Intangible Assets Other Changes

FiniteLivedIntangibleAssetsOtherChanges

-11000000

USD

CY2014

nrg

Finite Lived Intangible Assets Purchases

FiniteLivedIntangibleAssetsPurchases

182000000

USD

CY2015

nrg

Finite Lived Intangible Assets Purchases

FiniteLivedIntangibleAssetsPurchases

137000000

USD

CY2014

nrg

Finite Lived Intangible Assets Usage

FiniteLivedIntangibleAssetsUsage

34000000

USD

CY2015

nrg

Finite Lived Intangible Assets Usage

FiniteLivedIntangibleAssetsUsage

-95000000

USD

CY2014

nrg

Finite Lived Intangible Assets Write Off Of Fully Amortized Intangible Assets

FiniteLivedIntangibleAssetsWriteOffOfFullyAmortizedIntangibleAssets

843000000

USD

CY2015

nrg

Finite Lived Intangible Assets Write Off Of Fully Amortized Intangible Assets

FiniteLivedIntangibleAssetsWriteOffOfFullyAmortizedIntangibleAssets

-154000000

USD

CY2015Q4

nrg

Forty Four Percent Maximum Assessment

FortyFourPercentMaximumAssessment

0.44

pure

CY2014Q4

nrg

Funds Deposited By Counterparties

FundsDepositedByCounterparties

72000000

USD

CY2015Q4

nrg

Funds Deposited By Counterparties

FundsDepositedByCounterparties

106000000

USD

CY2013

nrg

Gains Losses On Extinguishment Of Debt Non Cash Portion

GainsLossesOnExtinguishmentOfDebtNonCashPortion

15000000

USD

CY2014

nrg

Gains Losses On Extinguishment Of Debt Non Cash Portion

GainsLossesOnExtinguishmentOfDebtNonCashPortion

-25000000

USD

CY2015

nrg

Gains Losses On Extinguishment Of Debt Non Cash Portion

GainsLossesOnExtinguishmentOfDebtNonCashPortion

75000000

USD

CY2013

nrg

Gross Receipts Tax

GrossReceiptsTax

88000000

USD

CY2014

nrg

Gross Receipts Tax

GrossReceiptsTax

108000000

USD

CY2015

nrg

Gross Receipts Tax

GrossReceiptsTax

110000000

USD

CY2015Q4

nrg

Guarantee Maturity Between One To Three Years

GuaranteeMaturityBetweenOneToThreeYears

93000000

USD

CY2015Q4

nrg

Guarantee Maturity Between Three To Five Years

GuaranteeMaturityBetweenThreeToFiveYears

257000000

USD

CY2015Q4

nrg

Guarantee Maturity Greater Than Five Years

GuaranteeMaturityGreaterThanFiveYears

723000000

USD

CY2015Q4

nrg

Guarantee Maturity Less Than One Year

GuaranteeMaturityLessThanOneYear

1805000000

USD

CY2014Q4

nrg

Guarantee Obligations Estimated Exposure

GuaranteeObligationsEstimatedExposure

3380000000

USD

CY2015Q4

nrg

Guarantee Obligations Estimated Exposure

GuaranteeObligationsEstimatedExposure

2878000000

USD

CY2013

nrg

Impairment Charges And Asset Write Downs

ImpairmentChargesAndAssetWriteDowns

-558000000

USD

CY2014

nrg

Impairment Charges And Asset Write Downs

ImpairmentChargesAndAssetWriteDowns

-97000000

USD

CY2015

nrg

Impairment Charges And Asset Write Downs

ImpairmentChargesAndAssetWriteDowns

-5086000000

USD

CY2013

nrg

Income Tax Reconciliation Change In Capital Loss Carryforwards Valuation Allowance

IncomeTaxReconciliationChangeInCapitalLossCarryforwardsValuationAllowance

10000000

USD

CY2015

nrg

Income Tax Reconciliation Expiration Capital Losses

IncomeTaxReconciliationExpirationCapitalLosses

0

USD

CY2014

nrg

Income Tax Reconciliation Change In Capital Loss Carryforwards Valuation Allowance

IncomeTaxReconciliationChangeInCapitalLossCarryforwardsValuationAllowance

0

USD

CY2015

nrg

Income Tax Reconciliation Change In Capital Loss Carryforwards Valuation Allowance

IncomeTaxReconciliationChangeInCapitalLossCarryforwardsValuationAllowance

0

USD

CY2013

nrg

Income Tax Reconciliation Expiration Capital Losses

IncomeTaxReconciliationExpirationCapitalLosses

10000000

USD

CY2014

nrg

Income Tax Reconciliation Expiration Capital Losses

IncomeTaxReconciliationExpirationCapitalLosses

0

USD

CY2013

nrg

Income Tax Reconciliation Impact Of Non Taxible Equity Earning

IncomeTaxReconciliationImpactOfNonTaxibleEquityEarning

-14000000

USD

CY2014

nrg

Income Tax Reconciliation Impact Of Non Taxible Equity Earning

IncomeTaxReconciliationImpactOfNonTaxibleEquityEarning

-11000000

USD

CY2015

nrg

Income Tax Reconciliation Impact Of Non Taxible Equity Earning

IncomeTaxReconciliationImpactOfNonTaxibleEquityEarning

-10000000

USD

CY2015

nrg

Income Taxes Threshold Percentage

IncomeTaxesThresholdPercentage

0.5

pure

CY2013

nrg

Increase Decrease In Notes Receivable

IncreaseDecreaseInNotesReceivable

-11000000

USD

CY2014

nrg

Increase Decrease In Notes Receivable

IncreaseDecreaseInNotesReceivable

25000000

USD

CY2015

nrg

Increase Decrease In Notes Receivable

IncreaseDecreaseInNotesReceivable

18000000

USD

CY2013

nrg

Increase Decrease In Restricted Cash To Support Equity Requirements For Us Doe Funded Projects

IncreaseDecreaseInRestrictedCashToSupportEquityRequirementsForUSDoeFundedProjects

26000000

USD

CY2014

nrg

Increase Decrease In Restricted Cash To Support Equity Requirements For Us Doe Funded Projects

IncreaseDecreaseInRestrictedCashToSupportEquityRequirementsForUSDoeFundedProjects

206000000

USD

CY2015

nrg

Increase Decrease In Restricted Cash To Support Equity Requirements For Us Doe Funded Projects

IncreaseDecreaseInRestrictedCashToSupportEquityRequirementsForUSDoeFundedProjects

-35000000

USD

CY2015Q4

nrg

Industry Mutual Insurance Company Multiplier

IndustryMutualInsuranceCompanyMultiplier

10

pure

CY2013

nrg

Inter Segment Sales

InterSegmentSales

2308000000

USD

CY2014

nrg

Inter Segment Sales

InterSegmentSales

1949000000

USD

CY2015

nrg

Inter Segment Sales

InterSegmentSales

1218000000

USD

CY2013

nrg

Intercompany Loans To Receipts From Subsidiaries

IntercompanyLoansToReceiptsFromSubsidiaries

0

USD

CY2014

nrg

Intercompany Loans To Receipts From Subsidiaries

IntercompanyLoansToReceiptsFromSubsidiaries

0

USD

CY2015

nrg

Intercompany Loans To Receipts From Subsidiaries

IntercompanyLoansToReceiptsFromSubsidiaries

0

USD

CY2013

nrg

Investments In Proceeds From Sales Of Unconsolidated Affiliates

InvestmentsInProceedsFromSalesOfUnconsolidatedAffiliates

0

USD

CY2014

nrg

Investments In Proceeds From Sales Of Unconsolidated Affiliates

InvestmentsInProceedsFromSalesOfUnconsolidatedAffiliates

-103000000

USD

CY2015

nrg

Investments In Proceeds From Sales Of Unconsolidated Affiliates

InvestmentsInProceedsFromSalesOfUnconsolidatedAffiliates

-395000000

USD

CY2015Q4

nrg

Longterm Debtexcluding Unamortized Discount Premiumnet

LongtermDebtexcludingUnamortizedDiscountPremiumnet

19496000000

USD

CY2014

nrg

Losson Extinguishmentof Preferred Stock

LossonExtinguishmentofPreferredStock

42000000

USD

CY2015

nrg

Maximum Remaining Termunder Individual Purchased Power Contract

MaximumRemainingTermunderIndividualPurchasedPowerContract

P5Y

CY2015Q4

nrg

Mutual Lost Revenue Insurance Maximum Weekly Recovery

MutualLostRevenueInsuranceMaximumWeeklyRecovery

3000000

USD

CY2015Q4

nrg

Mutual Property Insurance Additional Blanket Policy Property Coverage

MutualPropertyInsuranceAdditionalBlanketPolicyPropertyCoverage

1000000000

USD

CY2015Q4

nrg

Mutual Property Insurance Individual Maximum Property Coverage Limit

MutualPropertyInsuranceIndividualMaximumPropertyCoverageLimit

1500000000

USD

CY2015Q4

nrg

Net Credit Exposure

NetCreditExposure

733000000

USD

CY2014Q4

nrg

Net Deferred Tax Asset

NetDeferredTaxAsset

1500000000

USD

CY2015Q4

nrg

Net Deferred Tax Asset

NetDeferredTaxAsset

148000000

USD

CY2014

nrg

Noncashadjustmentforissuanceofconvertibledebt

23000000

USD

CY2015

nrg

Noncashadjustmentforissuanceofconvertibledebt

23000000

USD

CY2015

nrg

Noncontrolling Interest Contributionsfrom Noncontrolling Interest Holders

NoncontrollingInterestContributionsfromNoncontrollingInterestHolders

234000000

USD

CY2014Q4

nrg

Nuclear Decommissioning Trust Fund Liability Noncurrent

NuclearDecommissioningTrustFundLiabilityNoncurrent

333000000

USD

CY2015Q4

nrg

Nuclear Decommissioning Trust Fund Liability Noncurrent

NuclearDecommissioningTrustFundLiabilityNoncurrent

283000000

USD

CY2015Q4

nrg

Nuclear Insurance Financial Protection Pool Maximum Annual Assessment

NuclearInsuranceFinancialProtectionPoolMaximumAnnualAssessment

19000000

USD

CY2015Q4

nrg

Nuclear Insurance Financial Protection Pool Maximum Assessment

NuclearInsuranceFinancialProtectionPoolMaximumAssessment

127000000

USD

CY2015Q4

nrg

Nuclear Insurance Financial Protection Pool Maximum Assessment Adminstrative Fee Asa Percent

NuclearInsuranceFinancialProtectionPoolMaximumAssessmentAdminstrativeFeeAsaPercent

0.05

pure

CY2015Q4

nrg

Nuclear Insurance Financial Protection Pool Nuclear Operator Maximum Annual Assessment

NuclearInsuranceFinancialProtectionPoolNuclearOperatorMaximumAnnualAssessment

8000000

USD

CY2015Q4

nrg

Nuclear Insurance Financial Protection Pool Nuclear Operator Total Assessment

NuclearInsuranceFinancialProtectionPoolNuclearOperatorTotalAssessment

112000000

USD

CY2015Q4

nrg

Nuclear Insurance Financial Protection Pool Value

NuclearInsuranceFinancialProtectionPoolValue

13500000000

USD

CY2015Q4

nrg

Nuclear Insurance Per Incident Coverage Limit

NuclearInsurancePerIncidentCoverageLimit

13500000000

USD

CY2015Q4

nrg

Nuclear Insurance Requirement Per Site

NuclearInsuranceRequirementPerSite

375000000

USD

CY2012Q3

nrg

Number Of Pjm Transmission Owners Who Filed Motion

NumberOfPjmTransmissionOwnersWhoFiledMotion

3

CY2010Q2

nrg

Number Of Significant Orders Issued By Authority

NumberOfSignificantOrdersIssuedByAuthority

2

orders

CY2015

nrg

Number Of Years Board Of Directors Of Industry Mutual Insurance Company Can Adjust Policy After Policy Expires

NumberOfYearsBoardOfDirectorsOfIndustryMutualInsuranceCompanyCanAdjustPolicyAfterPolicyExpires

P6Y

CY2015

nrg

Payments To Settle Acquired Derivatives That Include Financing Elements

PaymentsToSettleAcquiredDerivativesThatIncludeFinancingElements

-196000000

USD

CY2015

nrg

Period Beyondwhich Comapny Can Not Predict Holdingof Collateral

PeriodBeyondwhichComapnyCanNotPredictHoldingofCollateral

P12M

CY2013

nrg

Operating Cost And Expense Excluding Depreciation Depletion And Amortization

OperatingCostAndExpenseExcludingDepreciationDepletionAndAmortization

9025000000

USD

CY2014

nrg

Operating Cost And Expense Excluding Depreciation Depletion And Amortization

OperatingCostAndExpenseExcludingDepreciationDepletionAndAmortization

12821000000

USD

CY2015

nrg

Operating Cost And Expense Excluding Depreciation Depletion And Amortization

OperatingCostAndExpenseExcludingDepreciationDepletionAndAmortization

11975000000

USD

CY2015Q4

nrg

Other Assets Noncurrent Emission Allowances

OtherAssetsNoncurrentEmissionAllowances

22000000

USD

CY2015

nrg

Other Comprehensive Income Loss Including Oc Ifor Nci

OtherComprehensiveIncomeLossIncludingOCIforNCI

-3000000

USD

CY2015

nrg

Payment Of Intercompany Dividends

PaymentOfIntercompanyDividends

201000000

USD

CY2013

nrg

Payments To Settle Acquired Derivatives That Include Financing Elements

PaymentsToSettleAcquiredDerivativesThatIncludeFinancingElements

-267000000

USD

CY2014

nrg

Payments To Settle Acquired Derivatives That Include Financing Elements

PaymentsToSettleAcquiredDerivativesThatIncludeFinancingElements

-9000000

USD

CY2015

nrg

Periodofretrospectivepremiumadjustments

P24M

CY2015Q4

nrg

Power Generation Capacity Megawatts

PowerGenerationCapacityMegawatts

49287

CY2015Q4

nrg

Preferred Stock Instrument Interest Rate Stated Percentage

PreferredStockInstrumentInterestRateStatedPercentage

2.822

pure

CY2014Q4

nrg

Preferred Stock Instrument Interest Rate Stated Percentage

PreferredStockInstrumentInterestRateStatedPercentage

3.625

pure

CY2014Q4

nrg

Prepaid Expense And Other Assets Current Less Accounts Receivable Affiliate

PrepaidExpenseAndOtherAssetsCurrentLessAccountsReceivableAffiliate

438000000

USD

CY2015Q4

nrg

Prepaid Expense And Other Assets Current Less Accounts Receivable Affiliate

PrepaidExpenseAndOtherAssetsCurrentLessAccountsReceivableAffiliate

438000000

USD

CY2013

nrg

Proceeds From Payments To Intercompany Loans

ProceedsFromPaymentsToIntercompanyLoans

0

USD

CY2014

nrg

Proceeds From Payments To Intercompany Loans

ProceedsFromPaymentsToIntercompanyLoans

0

USD

CY2015

nrg

Proceeds From Payments To Intercompany Loans

ProceedsFromPaymentsToIntercompanyLoans

0

USD

CY2013

nrg

Proceeds From Renewable Energy Grants

ProceedsFromRenewableEnergyGrants

55000000

USD

CY2014

nrg

Proceeds From Renewable Energy Grants

ProceedsFromRenewableEnergyGrants

916000000

USD

CY2015

nrg

Proceeds From Renewable Energy Grants

ProceedsFromRenewableEnergyGrants

82000000

USD

CY2014Q4

nrg

Property Plant And Equipment In Service

PropertyPlantAndEquipmentInService

29487000000

USD

CY2015Q4

nrg

Property Plant And Equipment In Service

PropertyPlantAndEquipmentInService

24909000000

USD

CY2014

nrg

Redeemable Noncontrolling Interest Cash Contributionsfrom Noncontrolling Interest Holders

RedeemableNoncontrollingInterestCashContributionsfromNoncontrollingInterestHolders

36000000

USD

CY2015

nrg

Redeemable Noncontrolling Interest Cash Contributionsfrom Noncontrolling Interest Holders

RedeemableNoncontrollingInterestCashContributionsfromNoncontrollingInterestHolders

27000000

USD

CY2014Q4

nrg

Redeemable Preferred Stock Fair Value

RedeemablePreferredStockFairValue

291000000

USD

CY2011Q4

nrg

Regulatory Charges Owed By Third Party

RegulatoryChargesOwedByThirdParty

22000000

USD

CY2012Q3

nrg

Regulatory Charges Settled By Third Party

RegulatoryChargesSettledByThirdParty

24000000

USD

CY2012Q3

nrg

Regulatory Charges Settled By Third Party Additional

RegulatoryChargesSettledByThirdPartyAdditional

1000000

USD

CY2013

nrg

Revenues From Resale Of Purchased Power

RevenuesFromResaleOfPurchasedPower

166000000

USD

CY2014

nrg

Revenues From Resale Of Purchased Power

RevenuesFromResaleOfPurchasedPower

387000000

USD

CY2015

nrg

Revenues From Resale Of Purchased Power

RevenuesFromResaleOfPurchasedPower

165000000

USD

CY2013

nrg

Reversal Of Previously Unrecognized Unrealized Gain Loss Acquired As Part Of Acquisition Trading Activity

ReversalOfPreviouslyUnrecognizedUnrealizedGainLossAcquiredAsPartOfAcquisitionTradingActivity

0

USD

CY2014

nrg

Reversal Of Previously Unrecognized Unrealized Gain Loss Acquired As Part Of Acquisition Trading Activity

ReversalOfPreviouslyUnrecognizedUnrealizedGainLossAcquiredAsPartOfAcquisitionTradingActivity

-32000000

USD

CY2015

nrg

Reversal Of Previously Unrecognized Unrealized Gain Loss Acquired As Part Of Acquisition Trading Activity

ReversalOfPreviouslyUnrecognizedUnrealizedGainLossAcquiredAsPartOfAcquisitionTradingActivity

-14000000

USD

CY2013

nrg

Reversal Previously Unrecognized Unrealized Gains Losses Acquired As Part Of Acquisition Economic Hedges

ReversalPreviouslyUnrecognizedUnrealizedGainsLossesAcquiredAsPartOfAcquisitionEconomicHedges

357000000

USD

CY2014

nrg

Reversal Previously Unrecognized Unrealized Gains Losses Acquired As Part Of Acquisition Economic Hedges

ReversalPreviouslyUnrecognizedUnrealizedGainsLossesAcquiredAsPartOfAcquisitionEconomicHedges

333000000

USD

CY2015

nrg

Reversal Previously Unrecognized Unrealized Gains Losses Acquired As Part Of Acquisition Economic Hedges

ReversalPreviouslyUnrecognizedUnrealizedGainsLossesAcquiredAsPartOfAcquisitionEconomicHedges

106000000

USD

CY2013

nrg

Reversal Previously Unrecognized Unrealized Gains Losses Settled Positions Economic Hedges

ReversalPreviouslyUnrecognizedUnrealizedGainsLossesSettledPositionsEconomicHedges

105000000

USD

CY2014

nrg

Reversal Previously Unrecognized Unrealized Gains Losses Settled Positions Economic Hedges

ReversalPreviouslyUnrecognizedUnrealizedGainsLossesSettledPositionsEconomicHedges

15000000

USD

CY2015

nrg

Reversal Previously Unrecognized Unrealized Gains Losses Settled Positions Economic Hedges

ReversalPreviouslyUnrecognizedUnrealizedGainsLossesSettledPositionsEconomicHedges

275000000

USD

CY2013

nrg

Reversal Previously Unrecognized Unrealized Gains Losses Settled Positions Trading Activity

ReversalPreviouslyUnrecognizedUnrealizedGainsLossesSettledPositionsTradingActivity

50000000

USD

CY2014

nrg

Reversal Previously Unrecognized Unrealized Gains Losses Settled Positions Trading Activity

ReversalPreviouslyUnrecognizedUnrealizedGainsLossesSettledPositionsTradingActivity

-1000000

USD

CY2015

nrg

Reversal Previously Unrecognized Unrealized Gains Losses Settled Positions Trading Activity

ReversalPreviouslyUnrecognizedUnrealizedGainsLossesSettledPositionsTradingActivity

46000000

USD

CY2015

nrg

Share Based Compensation Arrangement By Share Based Payment Award Number Of Types Of Awards

ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfTypesOfAwards

5

TypesOfAwards

CY2014Q4

nrg

Temporary Equity Liquidation Value

TemporaryEquityLiquidationValue

250

USD

CY2014

nrg

Unrealized Gain Loss On Derivatives Mark To Market Economic Hedging Activities

UnrealizedGainLossOnDerivativesMarkToMarketEconomicHedgingActivities

13000000

USD

CY2015Q4

nrg

Temporary Equity Liquidation Value

TemporaryEquityLiquidationValue

250

USD

CY2013

nrg

Unrealized Gain Loss On Derivatives Mark To Market Economic Hedging Activities

UnrealizedGainLossOnDerivativesMarkToMarketEconomicHedgingActivities

-285000000

USD

CY2015

nrg

Unrealized Gain Loss On Derivatives Mark To Market Economic Hedging Activities

UnrealizedGainLossOnDerivativesMarkToMarketEconomicHedgingActivities

-372000000

USD

CY2013

nrg

Unrealized Gain Loss On Derivatives Mark To Market Trading Activites

UnrealizedGainLossOnDerivativesMarkToMarketTradingActivites

-43000000

USD

CY2014

nrg

Unrealized Gain Loss On Derivatives Mark To Market Trading Activites

UnrealizedGainLossOnDerivativesMarkToMarketTradingActivites

14000000

USD

CY2015

nrg

Unrealized Gain Loss On Derivatives Mark To Market Trading Activites

UnrealizedGainLossOnDerivativesMarkToMarketTradingActivites

-76000000

USD

CY2015Q4

nrg

Variable Interest Entity Consolidated Carrying Amount Current Assets

VariableInterestEntityConsolidatedCarryingAmountCurrentAssets

84000000

USD

CY2015Q4

nrg

Variable Interest Entity Consolidated Carrying Amount Current Liabilities

VariableInterestEntityConsolidatedCarryingAmountCurrentLiabilities

56000000

USD

CY2015Q4

nrg

Variable Interest Entity Consolidated Carrying Amount Longterm Debt

VariableInterestEntityConsolidatedCarryingAmountLongtermDebt

366000000

USD

CY2015Q4

nrg

Variable Interest Entity Consolidated Carrying Amount Net Property Plantand Equipment

VariableInterestEntityConsolidatedCarryingAmountNetPropertyPlantandEquipment

1807000000

USD

CY2015Q4

nrg

Variable Interest Entity Consolidated Carrying Amount Noncontrolling Interest

VariableInterestEntityConsolidatedCarryingAmountNoncontrollingInterest

493000000

USD

CY2015Q4

nrg

Variable Interest Entity Consolidated Carrying Amount Other Longterm Assets

VariableInterestEntityConsolidatedCarryingAmountOtherLongtermAssets

863000000

USD

CY2015Q4

nrg

Variable Interest Entity Consolidated Carrying Amount Other Longterm Liabilities

VariableInterestEntityConsolidatedCarryingAmountOtherLongtermLiabilities

179000000

USD

CY2015Q4

nrg

Working Capital Facility Amount Drawn

WorkingCapitalFacilityAmountDrawn

14000000

USD

CY2014Q4

us-gaap

Accounts Payable Current

AccountsPayableCurrent

1060000000

USD

CY2015Q4

us-gaap

Accounts Payable Current

AccountsPayableCurrent

869000000

USD

CY2014Q4

us-gaap

Accounts Receivable Net Current

AccountsReceivableNetCurrent

1322000000

USD

CY2015Q4

us-gaap

Accounts Receivable Net Current

AccountsReceivableNetCurrent

1157000000

USD

CY2015Q4

us-gaap

Accrued Income Taxes Current

AccruedIncomeTaxesCurrent

5000000

USD

CY2014Q4

us-gaap

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

7890000000

USD

CY2015Q4

us-gaap

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

6804000000

USD

CY2012Q4

us-gaap

Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Net Of Tax

AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax

-31000000

USD

CY2013Q4

us-gaap

Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Net Of Tax

AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax

-23000000

USD

CY2014Q4

us-gaap

Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Net Of Tax

AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax

-68000000

USD

CY2015Q4

us-gaap

Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Net Of Tax

AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax

-101000000

USD

CY2013Q4

us-gaap

Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax

AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax

15000000

USD

CY2014Q4

us-gaap

Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax

AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax

1000000

USD

CY2015Q4

us-gaap

Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax

AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax

-10000000

USD

CY2014Q4

us-gaap

Accumulated Other Comprehensive Income Loss Net Of Tax

AccumulatedOtherComprehensiveIncomeLossNetOfTax

-174000000

USD

CY2015Q4

us-gaap

Accumulated Other Comprehensive Income Loss Net Of Tax

AccumulatedOtherComprehensiveIncomeLossNetOfTax

-173000000

USD

CY2014Q4

us-gaap

Additional Paid In Capital Common Stock

AdditionalPaidInCapitalCommonStock

8327000000

USD

CY2015Q4

us-gaap

Additional Paid In Capital Common Stock

AdditionalPaidInCapitalCommonStock

8296000000

USD

CY2013

us-gaap

Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value

AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

36000000

USD

CY2014

us-gaap

Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value

AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

45000000

USD

CY2015

us-gaap

Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value

AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

24000000

USD

CY2013

us-gaap

Advertising Expense

AdvertisingExpense

69000000

USD

CY2014

us-gaap

Advertising Expense

AdvertisingExpense

87000000

USD

CY2015

us-gaap

Advertising Expense

AdvertisingExpense

135000000

USD

CY2013

us-gaap

Allocated Share Based Compensation Expense

AllocatedShareBasedCompensationExpense

40000000

USD

CY2014

us-gaap

Allocated Share Based Compensation Expense

AllocatedShareBasedCompensationExpense

42000000

USD

CY2015

us-gaap

Allocated Share Based Compensation Expense

AllocatedShareBasedCompensationExpense

41000000

USD

CY2014Q4

us-gaap

Allowance For Doubtful Accounts Receivable Current

AllowanceForDoubtfulAccountsReceivableCurrent

23000000

USD

CY2015Q4

us-gaap

Allowance For Doubtful Accounts Receivable Current

AllowanceForDoubtfulAccountsReceivableCurrent

21000000

USD

CY2013

us-gaap

Amortization Of Financing Costs And Discounts

AmortizationOfFinancingCostsAndDiscounts

-33000000

USD

CY2014

us-gaap

Amortization Of Financing Costs And Discounts

AmortizationOfFinancingCostsAndDiscounts

-12000000

USD

CY2015

us-gaap

Amortization Of Financing Costs And Discounts

AmortizationOfFinancingCostsAndDiscounts

-11000000

USD

CY2013

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

279000000

USD

CY2014

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

268000000

USD

CY2015

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

277000000

USD

CY2015Q4

us-gaap

Amount Of Restricted Net Assets For Consolidated And Unconsolidated Subsidiaries

AmountOfRestrictedNetAssetsForConsolidatedAndUnconsolidatedSubsidiaries

5600000000

USD

CY2013

us-gaap

Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

25000000

shares

CY2014

us-gaap

Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

17000000

shares

CY2015

us-gaap

Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

22000000

shares

CY2013

us-gaap

Asset Impairment Charges

AssetImpairmentCharges

459000000

USD

CY2014

us-gaap

Asset Impairment Charges

AssetImpairmentCharges

97000000

USD

CY2015

us-gaap

Asset Impairment Charges

AssetImpairmentCharges

5030000000

USD

CY2014Q4

us-gaap

Asset Retirement Obligation

AssetRetirementObligation

763000000

USD

CY2015Q4

us-gaap

Asset Retirement Obligation

AssetRetirementObligation

945000000

USD

CY2015

us-gaap

Asset Retirement Obligation Accretion Expense

AssetRetirementObligationAccretionExpense

35000000

USD

CY2015

us-gaap

Asset Retirement Obligation Liabilities Settled

AssetRetirementObligationLiabilitiesSettled

-11000000

USD

CY2015

us-gaap

Asset Retirement Obligation Revision Of Estimate

AssetRetirementObligationRevisionOfEstimate

122000000

USD

CY2014Q4

us-gaap

Assets

40466000000

USD

CY2015Q4

us-gaap

Assets

32882000000

USD

CY2014Q4

us-gaap

Assets Current

AssetsCurrent

8408000000

USD

CY2015Q4

us-gaap

Assets Current

AssetsCurrent

7391000000

USD

CY2014Q4

us-gaap

Assets Noncurrent

AssetsNoncurrent

9691000000

USD

CY2015Q4

us-gaap

Assets Noncurrent

AssetsNoncurrent

6759000000

USD

CY2013

us-gaap

Available For Sale Securities Gross Realized Gains

AvailableForSaleSecuritiesGrossRealizedGains

25000000

USD

CY2014

us-gaap

Available For Sale Securities Gross Realized Gains

AvailableForSaleSecuritiesGrossRealizedGains

29000000

USD

CY2015

us-gaap

Available For Sale Securities Gross Realized Gains

AvailableForSaleSecuritiesGrossRealizedGains

21000000

USD

CY2013

us-gaap

Available For Sale Securities Gross Realized Losses

AvailableForSaleSecuritiesGrossRealizedLosses

8000000

USD

CY2014

us-gaap

Available For Sale Securities Gross Realized Losses

AvailableForSaleSecuritiesGrossRealizedLosses

8000000

USD

CY2015

us-gaap

Available For Sale Securities Gross Realized Losses

AvailableForSaleSecuritiesGrossRealizedLosses

14000000

USD

CY2014

us-gaap

Available For Sale Securities Gross Unrealized Gains

AvailableForSaleSecuritiesGrossUnrealizedGains

218000000

USD

CY2015

us-gaap

Available For Sale Securities Gross Unrealized Gains

AvailableForSaleSecuritiesGrossUnrealizedGains

202000000

USD

CY2014

us-gaap

Available For Sale Securities Gross Unrealized Loss

AvailableForSaleSecuritiesGrossUnrealizedLoss

2000000

USD

CY2015

us-gaap

Available For Sale Securities Gross Unrealized Loss

AvailableForSaleSecuritiesGrossUnrealizedLoss

3000000

USD

CY2014Q4

us-gaap

Business Acquisition Purchase Price Allocation Goodwill Expected Tax Deductible Amount

BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount

831000000

USD

CY2015Q4

us-gaap

Business Acquisition Purchase Price Allocation Goodwill Expected Tax Deductible Amount

BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount

620000000

USD

CY2013

us-gaap

Business Combination Acquisition Related Costs

BusinessCombinationAcquisitionRelatedCosts

128000000

USD

CY2014

us-gaap

Business Combination Acquisition Related Costs

BusinessCombinationAcquisitionRelatedCosts

84000000

USD

CY2015

us-gaap

Business Combination Acquisition Related Costs

BusinessCombinationAcquisitionRelatedCosts

10000000

USD

CY2013

us-gaap

Business Combination Integration Related Costs

BusinessCombinationIntegrationRelatedCosts

128000000

USD

CY2014

us-gaap

Business Combination Integration Related Costs

BusinessCombinationIntegrationRelatedCosts

84000000

USD

CY2015

us-gaap

Business Combination Integration Related Costs

BusinessCombinationIntegrationRelatedCosts

10000000

USD

CY2013

us-gaap

Capital Expenditures Incurred But Not Yet Paid

CapitalExpendituresIncurredButNotYetPaid

405000000

USD

CY2014

us-gaap

Capital Expenditures Incurred But Not Yet Paid

CapitalExpendituresIncurredButNotYetPaid

87000000

USD

CY2015

us-gaap

Capital Expenditures Incurred But Not Yet Paid

CapitalExpendituresIncurredButNotYetPaid

-24000000

USD

CY2012Q4

us-gaap

Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

2087000000

USD

CY2013Q4

us-gaap

Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

2254000000

USD

CY2014Q4

us-gaap

Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

2116000000

USD

CY2015Q4

us-gaap

Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

1518000000

USD

CY2013

us-gaap

Cash And Cash Equivalents Period Increase Decrease

CashAndCashEquivalentsPeriodIncreaseDecrease

167000000

USD

CY2014

us-gaap

Cash And Cash Equivalents Period Increase Decrease

CashAndCashEquivalentsPeriodIncreaseDecrease

-138000000

USD

CY2015

us-gaap

Cash And Cash Equivalents Period Increase Decrease

CashAndCashEquivalentsPeriodIncreaseDecrease

-598000000

USD

CY2015

us-gaap

Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months

CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths

-18000000

USD

CY2015Q4

us-gaap

Common Stock Capital Shares Reserved For Future Issuance

CommonStockCapitalSharesReservedForFutureIssuance

33979967

shares

CY2012Q3

us-gaap

Common Stock Dividends Per Share Cash Paid