XML 101 R86.htm IDEA: XBRL DOCUMENT
v3.21.1

Derivative Instruments and Hedging Activities - Credit-Risk-Related Contingent Features (Details) $ in Millions | Mar. 31, 2021 USD ($)
--- | ---
Derivatives, Fair Value [Line Items] |
Aggregate fair value – net liabilities | $ 247
Collateral posted | 212
Additional collateral for non-derivative transactions without extended unsecured credit | 24
Downgrade One Level from Current Ratings |
Derivatives, Fair Value [Line Items] |
Additional collateral | 11
Downgrade to Below Investment Grade from Current Ratings |
Derivatives, Fair Value [Line Items] |
Additional collateral | 55
Derivatives in net asset position additional collateral | 43
CECONY |
Derivatives, Fair Value [Line Items] |
Aggregate fair value – net liabilities | 236
Collateral posted | 206
CECONY | Downgrade One Level from Current Ratings |
Derivatives, Fair Value [Line Items] |
Additional collateral | 2
CECONY | Downgrade to Below Investment Grade from Current Ratings |
Derivatives, Fair Value [Line Items] |
Additional collateral | $ 47

X
- Definition The additional collateral that would be required for derivative instruments that are net assets. + References No definition available. + Details
Name: | ed_AdditionalCollateralForDerivativeNetAssets
Namespace Prefix: | ed_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Additional Collateral For Non-Derivative Transactions Without Extended Unsecured Credit + References No definition available. + Details
Name: | ed_AdditionalCollateralForNonDerivativeTransactionsWithoutExtendedUnsecuredCredit
Namespace Prefix: | ed_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period. + 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 (e) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624258-113959 + Details
Name: | us-gaap_AdditionalCollateralAggregateFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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=121590274&loc=SL5624258-113959 + Details
Name: | us-gaap_CollateralAlreadyPostedAggregateFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of credit risk derivative asset after deduction of credit risk derivative liability. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4K -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5708775-113959 + Details
Name: | us-gaap_CreditRiskDerivativesAtFairValueNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_DerivativesFairValueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

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

X
- Details
Name: | dei_LegalEntityAxis=ed_ConsolidatedEdisonCompanyofNewYorkInc.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |