Regulatory Matters - Regulatory Assets and Liabilities Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Regulatory Assets [Line Items]
Regulatory liabilities	$ 5,374	$ 5,444
Other customer-provided capital rate	4.75%	5.95%
Return on regulatory assets	$ 3,421	$ 3,262
Deferred derivative losses, current, recovery period (in years)	1 year
Deferred derivative losses, noncurrent, recovery period (in years)	3 years
Unrecognized pension and other postretirement costs period	10 years
Investment gains or losses is recognized in expense period	15 years
CECONY
Regulatory Assets [Line Items]
Regulatory liabilities	$ 4,879	4,940
Return on regulatory assets	$ 3,193	3,024
CECONY | Commodity
Regulatory Assets [Line Items]
Regulatory assets, recovery period	4 years
RECO
Regulatory Assets [Line Items]
Return on regulatory assets	$ 41	28
Net unbilled revenue deferrals
Regulatory Assets [Line Items]
Regulatory liabilities	$ 397	$ 436