Regulatory Matters - Regulatory Assets and Liabilities Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Regulatory Assets [Line Items]
Regulatory liabilities	$ 5,328	$ 6,027
Other customer-provided capital rate	5.20%	1.75%
Return on regulatory assets	$ 2,541	$ 2,304
Deferred derivative losses, current, recovery period (in years)	1 year
Deferred derivative losses, noncurrent, recovery period (in years)	3 years
CECONY
Regulatory Assets [Line Items]
Regulatory liabilities	$ 4,818	5,481
Return on regulatory assets	$ 2,359	2,097
CECONY | Commodity
Regulatory Assets [Line Items]
Regulatory assets, recovery period	4 years
RECO
Regulatory Assets [Line Items]
Return on regulatory assets	$ 24	21
Net unbilled revenue deferrals
Regulatory Assets [Line Items]
Regulatory liabilities	$ 278	$ 204