XML 50 R68.htm IDEA: XBRL DOCUMENT
v3.19.3

Fair Value of Financial Instruments - Derivative Fair Value Measurements (Details) $ in Millions | Sep. 30, 2019 USD ($) $ / MWh | Dec. 31, 2018 USD ($) $ / MWh
--- | --- | ---
Liabilities |  |
Derivative liabilities | $ 1,032 | $ 977
Level 3 |  |
Liabilities |  |
Derivative liabilities | 110 | 89
Commodity contracts |  |
Assets |  |
Derivative assets | 1,093 | 1,042
Liabilities |  |
Derivative liabilities | 1,032 | 977
Commodity contracts | Level 3 |  |
Assets |  |
Derivative assets | 123 | 109
Liabilities |  |
Derivative liabilities | 110 | 89
Commodity contracts | Level 3 | Power Contracts |  |
Assets |  |
Derivative assets | 89 | 89
Liabilities |  |
Derivative liabilities | $ 98 | $ 75
Commodity contracts | Level 3 | Power Contracts | Low |  |
Fair Value Inputs / Range |  |
Forward Market Price (per MWh) | $ / MWh | 6 | 1
Commodity contracts | Level 3 | Power Contracts | High |  |
Fair Value Inputs / Range |  |
Forward Market Price (per MWh) | $ / MWh | 217 | 214
Commodity contracts | Level 3 | Power Contracts | Weighted Average |  |
Fair Value Inputs / Range |  |
Forward Market Price (per MWh) | $ / MWh | 22 | 31
Commodity contracts | Level 3 | FTRs |  |
Assets |  |
Derivative assets | $ 34 | $ 20
Liabilities |  |
Derivative liabilities | $ 12 | $ 14
Commodity contracts | Level 3 | FTRs | Low |  |
Fair Value Inputs / Range |  |
Derivative, Auction Price | $ / MWh | (134) | (90)
Commodity contracts | Level 3 | FTRs | High |  |
Fair Value Inputs / Range |  |
Derivative, Auction Price | $ / MWh | 60 | 34
Commodity contracts | Level 3 | FTRs | Weighted Average |  |
Fair Value Inputs / Range |  |
Derivative, Auction Price | $ / MWh | 0 | 0

X
- Definition Derivative, Auction Price + References No definition available. + Details
Name: | nrg_DerivativeAuctionPrice
Namespace Prefix: | nrg_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AssetsFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=118948506&loc=SL51823488-111719 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=118948506&loc=SL51823488-111719 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The forward price on the price risk forward or futures contract, such as a gas futures contract. + References No definition available. + Details
Name: | us-gaap_DerivativeForwardPrice
Namespace Prefix: | us-gaap_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_FairValueInputsQuantitativeInformationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_LiabilitiesFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
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: | nrg_DerivativesByUnderlyingAssetsAxis=nrg_PowerContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | nrg_DerivativesByUnderlyingAssetsAxis=nrg_FinancialTransmissionRightsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |