XML 67 R43.htm IDEA: XBRL DOCUMENT
v3.20.1

Summary of Significant Accounting Policies and Other Matters - Utility Plant (Details) - USD ($) $ in Millions | Mar. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Finite-Lived Intangible Assets [Line Items] |  |
Accumulated amortization | $ 152 | $ 126
Software Licenses |  |
Finite-Lived Intangible Assets [Line Items] |  |
Gross asset | 91 | 93
Accumulated amortization | 12 | 10
CECONY | Software Licenses |  |
Finite-Lived Intangible Assets [Line Items] |  |
Gross asset | 87 | 88
Estimated aggregate annual amortization expense | 7 |
Accumulated amortization | $ 11 | $ 10

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 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 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_FiniteLivedIntangibleAssetsLineItems
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: | dei_LegalEntityAxis=ed_ConsolidatedEdisonCompanyofNewYorkInc.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |