XML 170 R152.htm IDEA: XBRL DOCUMENT
v3.20.4

Guarantees - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019
Guarantor Obligations |  |
Guarantee obligation | $ 1,746 | $ 2,010
Letters of credit and surety bonds |  |
Guarantor Obligations |  |
Guarantee obligation | $ 1,153 | 1,024
Letters of credit and surety bonds, maximum expiration period (in years) | 1 year |
Asset sales guarantee obligations |  |
Guarantor Obligations |  |
Guarantee obligation | $ 506 | $ 698
California property tax indemnity | $ 176 |

X
- Definition The estimated amount of future payments the guarantor could be required to make under guarantees, indemnities and other contingent liability obligations. + References No definition available. + Details
Name: | nrg_GuaranteeObligationsEstimatedExposure
Namespace Prefix: | nrg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition This element represents the maximum expiration period of letters of credit and surety bonds for entity is contingently obliged. + References No definition available. + Details
Name: | nrg_GuaranteeObligationsLettersofCreditandSuretyBondsMaximumExpirationPeriod
Namespace Prefix: | nrg_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12069-110248 + Details
Name: | us-gaap_GuaranteeObligationsCurrentCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_GuaranteeObligationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=nrg_LettersOfCreditAndSuretyBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=nrg_AssetSalesGuaranteeObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |