Related Party Transactions - Additional Information (Details) MMBTU in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) MMBTU	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Related Party Transaction [Line Items]
Net assets	$ 21,158,000,000	$ 20,687,000,000
Other income	834,000,000	402,000,000	$ 22,000,000
Unconditional charitable contribution, accrued amount	12,000,000
CECONY
Related Party Transaction [Line Items]
Net assets	19,146,000,000	16,878,000,000	16,312,000,000	$ 14,849,000,000
Sale of natural gas	82,000,000	144,000,000	$ 90,000,000
Tax expense due to affiliates	110,000,000	(89,000,000)
Funding limit of CECONY to O&R (not to exceed)	$ 250,000,000
CECONY | Related Party, Lending of Funds
Related Party Transaction [Line Items]
Lending period (not more than) (months)	12 months
CECONY | Equity Method Investee | Mountain Valley Pipeline
Related Party Transaction [Line Items]
Contract term (years)	20 years
Generating capacity per day (in dekatherms) | MMBTU	250
CECONY | Affiliated Entity | Financial Electric Capacity Contract | Con Edison Energy
Related Party Transaction [Line Items]
Gain (loss) on financial electric capacity contracts	$ 5,000,000
O&R
Related Party Transaction [Line Items]
Net assets	1,062,000,000
Outstanding loans	$ 0	0
CET Electric | NY Transco
Related Party Transaction [Line Items]
Ownership interest, percentage	45.70%
CET Electric | NY Transco | Related Party
Related Party Transaction [Line Items]
Other income	$ 7,300,000	$ 8,000,000
CET Electric | New York Transco's Propel NY Energy Project
Related Party Transaction [Line Items]
Ownership interest, percentage	41.70%