XML 81 R69.htm IDEA: XBRL DOCUMENT
v3.19.1

Accounting for Derivative Instruments and Hedging Activities - Pre-tax effects of economic hedges not designated a cash flow hedges (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2019 | Mar. 31, 2018
Unrealized mark-to-market results |  |
Reversal of previously recognized unrealized losses on settled positions related to economic hedges | $ 19 | $ 1
Reversal of acquired gain positions related to economic hedges | (2) | 0
Net unrealized gains on open positions related to economic hedges | 3 | 205
Total unrealized mark-to-market gains for economic hedging activities | 20 | 206
Reversal of previously recognized unrealized gains on settled positions related to trading activity | (6) | (3)
Net unrealized gains on open positions related to trading activity | 13 | 11
Total unrealized mark-to-market gains for trading activity | 7 | 8
Total unrealized gains | 27 | 214
Credit Risk Related Contingent Features |  |
Unrealized gain (loss) from open economic hedge positions | 3 | 205
Collateral due on net liability position that has not been called by a certain marginable agreement counterparty | 3 |
Adequate Assurance Clauses |  |
Credit Risk Related Contingent Features |  |
Derivative net liability position, collateral required Contracts with Credit Rating Contingent Feature | 17 |
Credit Rating Contingent Features |  |
Credit Risk Related Contingent Features |  |
Derivative net liability position, collateral required Contracts with Credit Rating Contingent Feature | 23 |
Commodity contracts |  |
Unrealized mark-to-market results |  |
Total unrealized gains | 27 | 214
Commodity contracts | Operating revenues |  |
Unrealized mark-to-market results |  |
Total unrealized gains | 27 | (88)
Commodity contracts | Cost of operations |  |
Unrealized mark-to-market results |  |
Total unrealized gains | 0 | 302
Interest rate contracts |  |
Unrealized mark-to-market results |  |
Total unrealized gains | $ (9) | $ 12

X
- Definition -- None. No documentation exists for this element. -- + References No definition available. + Details
Name: | nrg_CreditRiskRelatedContingentFeaturesAbstract
Namespace Prefix: | nrg_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents the amount recorded in the entity's statement of operations for net unrealized gains (losses) on open positions related to trading activities. + References No definition available. + Details
Name: | nrg_DerivativeUnrealizedGainsOnOpenPositionsRelatedToTradingActivityNet
Namespace Prefix: | nrg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount reversed into entity's statement of operations for previously recognized unrealized (gains) losses on settled positions related to acquired economic hedges. + References No definition available. + Details
Name: | nrg_ReversalPreviouslyRecognizedUnrealizedGainsLossesAcquiredasPartofAcquisitionEconomicHedges
Namespace Prefix: | nrg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount reversed into entity's statement of operations for previously recognized unrealized (gains) losses on settled positions related to economic hedges. + References No definition available. + Details
Name: | nrg_ReversalPreviouslyRecognizedUnrealizedGainsLossesSettledPositionsEconomicHedges
Namespace Prefix: | nrg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount reversed into entity's statement of operations for previously recognized unrealized (gains) losses on settled positions related to trading activities. + References No definition available. + Details
Name: | nrg_ReversalPreviouslyUnrecognizedUnrealizedGainsLossesSettledPositionsTradingActivity
Namespace Prefix: | nrg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Unrealized Gain (Loss) on Derivatives, Mark To Market, Economic Hedging Activities + References No definition available. + Details
Name: | nrg_UnrealizedGainLossOnDerivativesMarkToMarketEconomicHedgingActivities
Namespace Prefix: | nrg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Unrealized Gain (Loss) on Derivatives, Mark To Market, Trading Activities + References No definition available. + Details
Name: | nrg_UnrealizedGainLossonDerivativesMarkToMarketTradingActivities
Namespace Prefix: | nrg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition -- None. No documentation exists for this element. -- + References No definition available. + Details
Name: | nrg_UnrealizedMarkToMarketResultsAbstract
Namespace Prefix: | nrg_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4H -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624258-113959 + Details
Name: | us-gaap_CollateralAlreadyPostedAggregateFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4CC -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109998890-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4H -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624258-113959 + Details
Name: | us-gaap_DerivativeNetLiabilityPositionAggregateFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of unrealized gain (loss) related to derivatives designated as cash flow hedging instruments, recorded in results of operations to the extent that the cash flow hedge is determined to be ineffective. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 + Details
Name: | us-gaap_UnrealizedGainLossOnCashFlowHedgingInstruments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 + Details
Name: | us-gaap_UnrealizedGainLossOnDerivatives
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_CreditDerivativesByContractTypeAxis=nrg_AdequateAssuranceClausesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditDerivativesByContractTypeAxis=nrg_CreditRatingContingentFeaturesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CommodityContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_SalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_CostOfSalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |