XML 134 R133.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2

Derivative Instruments and Hedging Activities - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Investment Holdings [Line Items]
Energy supply and hedging activities credit exposure total	$ 128
Makeup of net credit exposure with investment-grade counterparties	24
Makeup of net credit exposure independent system operators	62
Makeup of net credit exposure with commodity exchange brokers	15
Makeup of net credit exposure non-investment grade/non-rated counterparties	27
CECONY
Investment Holdings [Line Items]
Energy supply and hedging activities credit exposure total	8
Makeup of net credit exposure with commodity exchange brokers	$ 8

X

- Definition

Credit Exposure Independent System Operators

+ References

No definition available.

+ Details

Name:	ed_CreditExposureIndependentSystemOperators
Namespace Prefix:	ed_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Credit exposure nonrated counterparties

+ References

No definition available.

+ Details

Name:	ed_CreditExposureNonratedCounterParties
Namespace Prefix:	ed_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Maximum Potential Future Exposure On Credit Risk Derivatives With Commodity Exchange Brokers

+ References

No definition available.

+ Details

Name:	ed_MaximumPotentialFutureExposureOnCreditRiskDerivativesWithCommodityExchangeBrokers
Namespace Prefix:	ed_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Maximum Potential Future Exposure On Credit Risk Derivatives With Investment Grade Counterparties

+ References

No definition available.

+ Details

Name:	ed_MaximumPotentialFutureExposureOnCreditRiskDerivativesWithInvestmentGradeCounterparties
Namespace Prefix:	ed_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Maximum potential amount of future undiscounted payments that could be required under the credit derivative, before reduction for potential recoveries under recourse or collateralization provisions.

+ 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 (b)(1)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5708775-113959

+ Details

Name:	us-gaap_CreditDerivativeMaximumExposureUndiscounted
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_InvestmentHoldingsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

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