Public Utilities, Requested Equity Capital Structure, Rate Increase (Decrease), Percentage

No definition available.

Name:	ed_PublicUtilitiesRequestedEquityCapitalStructureRateIncreaseDecreasePercentage
Namespace Prefix:	ed_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

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

- Definition

Amount of public utility's interim rate increase (decrease) allowed while waiting final decision of regulatory agency.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesInterimRateIncreaseDecreaseAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage of public utility's interim rate increase (decrease) allowed while waiting final decision of regulatory agency.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesInterimRateIncreaseDecreasePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of public utility's requested equity to capital, including debt and equity.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesRequestedEquityCapitalStructurePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of public utility's requested rate increase (decrease) with regulatory agency.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage of public utility's requested return on equity.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesRequestedReturnOnEquityPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_PublicUtilityAxis=us-gaap_ElectricTransmissionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=ed_CeconyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilityAxis=us-gaap_GasTransmissionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Regulatory Matters - Additional Information (Detail) - CECONY - USD ($) $ in Millions	1 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2016
Electric \| Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Interim rate increase (decrease), amount	$ 141	$ 180
Interim rate increase (decrease), percent	9.75%	9.75%
Requested equity capital structure, rate increase (decrease) (percent)	48.00%	48.00%
Gas \| Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Interim rate increase (decrease), amount	$ 109	$ 97
Interim rate increase (decrease), percent	9.75%	9.75%
Requested equity capital structure, rate increase (decrease) (percent)	48.00%	48.00%
Subsequent Event \| Electric
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease) amount			$ 482
Requested return on equity (percent)			9.75%
Requested equity capital structure (percent)			48.00%
Subsequent Event \| Gas
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease) amount			$ 154
Requested return on equity (percent)			9.75%
Requested equity capital structure (percent)			48.00%