Related Party Transactions - Additional Information (Details) MMBTU in Thousands	1 Months Ended		12 Months Ended
	Dec. 31, 2024 USD ($)	Apr. 30, 2024 USD ($)	Dec. 31, 2024 USD ($) MMBTU	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Related Party Transaction [Line Items]
Other income			$ 635,000,000	$ 834,000,000	$ 402,000,000
Unconditional charitable contribution, accrued amount	$ 12,000,000	$ 12,000,000
CECONY
Related Party Transaction [Line Items]
Net assets	19,971,000,000		19,971,000,000	19,146,000,000	16,878,000,000	$ 16,312,000,000
Sale of natural gas			77,000,000	82,000,000	$ 144,000,000
Tax expense due to affiliates			344,000,000	110,000,000
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]
Other income			$ 28,000,000
Contract term (years)			20 years
Generating capacity per day (in dekatherms) | MMBTU			200
O&R
Related Party Transaction [Line Items]
Net assets	1,142,000,000		$ 1,142,000,000
Outstanding loans	$ 0		0	0
CET Electric | NY Transco | Related Party
Related Party Transaction [Line Items]
Other income			$ 0	$ 7,300,000