Current Expected Credit Losses - Additional Information (Details) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (decrease) in allowance for uncollectible accounts resulting from COVID-19 pandemic	$ (1,000,000)	$ 40,000,000	$ (5,000,000)	$ 74,000,000
Subsidiaries \| CECONY
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (decrease) in allowance for uncollectible accounts resulting from COVID-19 pandemic	$ 0	$ 36,000,000		$ 66,000,000

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.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 40
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481628/310-20-40-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

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