Related Party Transactions - Additional Information (Details) MMBTU in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) MMBTU	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Related Party Transaction [Line Items]
Net assets	$ 20,687,000,000	$ 20,037,000,000
CECONY
Related Party Transaction [Line Items]
Net assets	16,878,000,000	16,312,000,000	$ 14,849,000,000	$ 14,147,000,000
Sale of natural gas	144,000,000	90,000,000	59,000,000
Tax expense due to affiliates	89,000,000	10,000,000
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]
Amount of transaction	$ 0	0
Contract term (years)	20 years
Generating capacity per day (in dekatherms) | MMBTU	250
CECONY | Equity Method Investee | Stagecoach | Purchased Power Costs
Related Party Transaction [Line Items]
Amount of transaction		$ 31,000,000	$ 34,000,000
Percentage of equity interest owned		50.00%
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	$ (4,000,000)
O&R
Related Party Transaction [Line Items]
Net assets	931,000,000
Outstanding loans	$ 0	0
CET Electric | NY Transco
Related Party Transaction [Line Items]
Ownership interest, percentage	45.70%
Amounts billed	$ 8,000,000	$ 5,900,000
CET Gas | Mountain Valley Pipeline
Related Party Transaction [Line Items]
Percentage of equity interest owned	9.60%	10.20%	11.30%
Expected reduction in equity interest	8.00%