Regulatory Matters - Regulatory Assets and Liabilities Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Regulatory Assets [Line Items]
Regulatory liabilities	$ 5,444	$ 5,328
Other customer-provided capital rate	5.95%	5.20%
Return on regulatory assets	$ 3,262	$ 2,541
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	$ 4,940	4,818
Return on regulatory assets	$ 3,024	2,359
CECONY | Commodity
Regulatory Assets [Line Items]
Regulatory assets, recovery period	4 years
RECO
Regulatory Assets [Line Items]
Return on regulatory assets	$ 28	24
Net unbilled revenue deferrals
Regulatory Assets [Line Items]
Regulatory liabilities	$ 436	$ 278