XML 83 R58.htm IDEA: XBRL DOCUMENT
v3.20.4

Summary of Significant Accounting Policies and Other Matters - Plant and Depreciation (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Accumulated amortization | $ 228 | $ 126 |
Annual aggregate depreciation allowance | 1,694 |  |
Other deferred charges and noncurrent assets | 54 |  |
Prepaid Expense | 12 |  |
Depreciation expense, other deferred charges and noncurrent assets and prepayments | 7 |  |
Accumulated depreciation, other deferred charges and noncurrent assets and prepayments | 10 |  |
Software Licenses |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Gross asset | 86 | 93 |
Estimated aggregate annual amortization expense | 7 |  |
Accumulated amortization | $ 17 | $ 10 |
Non-Utility Plant | Maximum | Land And Conduit |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 10 years |  |
Non-Utility Plant | Maximum | Wind Power Generating Assets |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 30 years |  |
Non-Utility Plant | Maximum | Solar Powered Generating Assets |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 35 years |  |
CECONY |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
AFUDC rates (percent) | 5.20% | 5.10% | 5.40%
Average depreciation rates (percent) | 3.50% | 3.20% | 3.20%
Annual aggregate depreciation allowance | $ 1,604 |  |
Other deferred charges and noncurrent assets | 51 |  |
Prepaid Expense | 11 |  |
Depreciation expense, other deferred charges and noncurrent assets and prepayments | 6 |  |
Accumulated depreciation, other deferred charges and noncurrent assets and prepayments | 8 |  |
CECONY | Software Licenses |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Gross asset | 81 | $ 88 |
Estimated aggregate annual amortization expense | 7 |  |
Accumulated amortization | $ 17 | $ 10 |
CECONY | Electric | Minimum |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 5 years |  |
CECONY | Electric | Maximum |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 85 years |  |
CECONY | Gas | Minimum |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 5 years |  |
CECONY | Gas | Maximum |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 90 years |  |
CECONY | Steam | Minimum |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 5 years |  |
CECONY | Steam | Maximum |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 80 years |  |
CECONY | General Plant | Minimum |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 5 years |  |
CECONY | General Plant | Maximum |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 55 years |  |
O&R |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
AFUDC rates (percent) | 5.30% | 5.30% | 2.20%
Average depreciation rates (percent) | 3.20% | 3.00% | 2.90%
O&R | Electric | Minimum |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 5 years |  |
O&R | Electric | Maximum |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 75 years |  |
O&R | General Plant | Minimum |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 5 years |  |
O&R | General Plant | Maximum |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Estimated useful lives (years) | 50 years |  |

X
- Definition Accumulated Depreciation, Other Deferred Charges And Noncurrent Assets And Prepayments + References No definition available. + Details
Name: | ed_AccumulatedDepreciationOtherDeferredChargesAndNoncurrentAssetsAndPrepayments
Namespace Prefix: | ed_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Depreciation Expense, Other Deferred Charges And Noncurrent Assets And Prepayments + References No definition available. + Details
Name: | ed_DepreciationExpenseOtherDeferredChargesAndNoncurrentAssetsAndPrepayments
Namespace Prefix: | ed_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Finite-Lived Intangible Assets, Annual Amortization Expense + References No definition available. + Details
Name: | ed_FiniteLivedIntangibleAssetsAnnualAmortizationExpense
Namespace Prefix: | ed_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Other Deferred Charges And Noncurrent Assets + References No definition available. + Details
Name: | ed_OtherDeferredChargesAndNoncurrentAssets
Namespace Prefix: | ed_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Public Utilities, Depreciation Allowance, Current Rate Plans + References No definition available. + Details
Name: | ed_PublicUtilitiesDepreciationAllowanceCurrentRatePlans
Namespace Prefix: | ed_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
Name: | us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 928 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6473545&loc=d3e61844-108004 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
Name: | us-gaap_FiniteLivedIntangibleAssetsGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of expenditures made in advance of when the economic benefit of the cost will be realized, and which will be expensed in future periods with the passage of time or when a triggering event occurs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.10) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.10) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 + Details
Name: | us-gaap_PrepaidExpenseCurrentAndNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Effective rate, including composite rate, of cost of financing additions to qualifying regulated assets, commonly called allowance for funds used during construction. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 835 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6501662&loc=d3e56162-110433 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 835 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6501569&loc=d3e55921-110430 + Details
Name: | us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Composite depreciation rate for public utility plants in service. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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_PublicUtilityPropertyPlantAndEquipmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_ComputerSoftwareIntangibleAssetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=ed_NonUtilityPlantMember
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: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=ed_LandAndConduitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=ed_WindPowerGeneratingAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=ed_SolarPoweredGeneratingAssetsMember
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: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=us-gaap_ElectricityGenerationPlantNonNuclearMember
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: | us-gaap_PublicUtilityAxis=us-gaap_GasTransmissionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=us-gaap_SteamPlantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=ed_GeneralUtilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=ed_OrangeAndRocklandUtilitiesIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |