Revenue Requirement

No definition available.

Name:	ed_RevenueRequirement
Namespace Prefix:	ed_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The expense charged against earnings during the period to allocate the capitalized costs of regulatory assets over the periods expected to benefit from such costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.3)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

Name:	us-gaap_AmortizationOfRegulatoryAsset
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of refund payments made to customers during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 13.A.4(a))

-URI http://asc.fasb.org/extlink&oid=27012821&loc=d3e214044-122780

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 13

-Section A

-Paragraph a

-Subsection 4

+ Details

Name:	us-gaap_CustomerRefundableFeesRefundPayments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The increase (decrease) during the reporting period in the public utility damage costs that will be permitted by regulatory agencies to be recovered from rate payers.

+ References

+ Details

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

- Details

Name:	us-gaap_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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_RegulatoryAssetAxis=ed_DeferredStormCostsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryLiabilityAxis=ed_StormReserveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Regulatory Matters - Summary of Rate Plan (CECONY-Electric) (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2015
Deferred Storm Costs [Member]
Public Utilities, General Disclosures [Line Items]
Reduction of costs recoverable from customers	$ 4
Electric [Member] \| CECONY [Member]
Public Utilities, General Disclosures [Line Items]
Potential refund from customers	249
Electric [Member] \| Deferred Storm Costs [Member] \| CECONY [Member]
Public Utilities, General Disclosures [Line Items]
Annual amortization of regulatory asset	107
Reduction of costs recoverable from customers	4
Storm Reserve [Member] \| Electric [Member] \| CECONY [Member]
Public Utilities, General Disclosures [Line Items]
Revenue requirement		21
Storm Reserve [Member] \| Electric [Member] \| Scenario, Forecast [Member] \| CECONY [Member]
Public Utilities, General Disclosures [Line Items]
Revenue requirement			$ 21