Regulatory Matters - Schedule of Utilities Rate Plans (CECONY-Electric) (Details) - USD ($) $ in Thousands	12 Months Ended			36 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2028	Dec. 31, 2025	Dec. 31, 2022
Public Utilities, General Disclosures [Line Items]
Positive incentives	$ 16,918,000	$ 15,256,000	$ 14,663,000
Revenue decoupling mechanisms	0	0	0		$ 0	$ 3,000
CECONY
Public Utilities, General Disclosures [Line Items]
Positive incentives	15,651,000	14,129,000	13,476,000
CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Retention of annual transmission congestion revenues					75,000
Actual earnings adjustment mechanism incentives	35,000	52,000	34,000
Revenue decoupling mechanisms	83,000	164,000	162,000		83,000
Regulatory reconciliations	287,000	52,000	140,000		287,000
Deferred regulatory asset (liability)	$ 12,000	(25,000)	$ 1,000		$ 12,000
Authorized return on common equity					9.25%
Earnings sharing	9.75%				9.75%
Common equity ratio					48.00%
Percent of total customer bill impact per commodity (no more than)	0.50%				0.50%
Deferrals for property taxes limitation from rates (percent)					90.00%
CECONY | Electric | Gas Leak Backlog, Leak Prone Pipe and Service Terminations
Public Utilities, General Disclosures [Line Items]
Positive incentives		$ 7,000
CECONY | Electric | Protected Portion
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					$ 1,512,000
CECONY | Electric | Over Two Years
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA					256,000
CECONY | Electric | Over Two Years | Unprotected Portion
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					306,000
CECONY | Electric | Annually | Unprotected Portion
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					153,000
CECONY | Electric | Deferred Project Costs | Annually
Public Utilities, General Disclosures [Line Items]
Amortizations to income of net regulatory (assets) and liabilities					31,000
CECONY | Electric | Deferred Project Costs | Over Three Years
Public Utilities, General Disclosures [Line Items]
Amortizations to income of net regulatory (assets) and liabilities					93,000
CECONY | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Retention of annual transmission congestion revenues				$ 75,000
Authorized return on common equity				9.40%
Earnings sharing				9.90%
Common equity ratio				48.00%
Electric base rate percentage				2.80%
Recovery deferral (percent)				80.00%
Maximum deferral (percent)				15.00%
CECONY | Electric | Year 1
Public Utilities, General Disclosures [Line Items]
Base rate changes	$ 442,000				442,000
Amortizations to income of net regulatory (assets) and liabilities					104,000
Potential earnings adjustment mechanism incentives					70,000
Negative revenue adjustments					516,000
Average rate base					$ 26,095,000
Weighted average cost of capital (after-tax)					6.75%
Actual return on common equity, percent					9.46%
Cost of long-term debt	4.46%				4.46%
Deferral, annual maximum (not more than) (percent)					0.10%
CECONY | Electric | Year 1 | Protected Portion
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					$ 34,000
Actual net expenses amount					8,500
CECONY | Electric | Year 1 | Over Seven To Fifteen Years
Public Utilities, General Disclosures [Line Items]
Recovery of energy efficiency and savings program costs					457,000
Amount of cost recovery					244,000
CECONY | Electric | Year 1 | Over Two Years
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA					128,000
CECONY | Electric | Year 1 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					27,847,000
CECONY | Electric | Year 1 | Advanced metering infrastructure (AMI)
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					744,000
CECONY | Electric | Year 1 | Customer Service Systems (CSS)
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					11,000
CECONY | Electric | Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes				$ 222,000
Amortizations to income of net regulatory (assets) and liabilities				88,000
Potential earnings adjustment mechanism incentives				40,000
Negative revenue adjustments				651,000
Average rate base				$ 32,935,000
Weighted average cost of capital (after-tax)				6.98%
Cost of long-term debt				4.78%
Requested rate increase (decrease), amount				$ 234,000
Reflects regulatory liability amortization				63,000
CECONY | Electric | Year 1 | Scenario, Forecast | Protected Portion
Public Utilities, General Disclosures [Line Items]
Reflects regulatory liability amortization				24,000
CECONY | Electric | Year 1 | Scenario, Forecast | Unprotected Portion
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA				1,000
CECONY | Electric | Year 1 | Scenario, Forecast | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations				33,590,000
CECONY | Electric | Year 2
Public Utilities, General Disclosures [Line Items]
Base rate changes	$ 518,000				518,000
Amortizations to income of net regulatory (assets) and liabilities					49,000
Potential earnings adjustment mechanism incentives					75,000
Negative revenue adjustments					557,000
Average rate base					$ 27,925,000
Weighted average cost of capital (after-tax)					6.79%
Actual return on common equity, percent					9.21%
Cost of long-term debt	4.54%				4.54%
Deferral, annual maximum (not more than) (percent)					500.00%
CECONY | Electric | Year 2 | Protected Portion
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					$ 63,000
Actual net expenses amount					12,750
CECONY | Electric | Year 2 | Over Seven To Fifteen Years
Public Utilities, General Disclosures [Line Items]
Recovery of energy efficiency and savings program costs					457,000
Amount of cost recovery					237,000
CECONY | Electric | Year 2 | Over Two Years
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA					128,000
CECONY | Electric | Year 2 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					29,884,000
CECONY | Electric | Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes				473,000
Amortizations to income of net regulatory (assets) and liabilities				81,000
Potential earnings adjustment mechanism incentives				42,000
Negative revenue adjustments				685,000
Average rate base				$ 35,149,000
Weighted average cost of capital (after-tax)				7.04%
Cost of long-term debt				4.90%
Requested rate increase (decrease), amount				$ 410,000
Reflects regulatory liability amortization				58,000
CECONY | Electric | Year 2 | Scenario, Forecast | Protected Portion
Public Utilities, General Disclosures [Line Items]
Reflects regulatory liability amortization				22,000
CECONY | Electric | Year 2 | Scenario, Forecast | Unprotected Portion
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA				1,000
CECONY | Electric | Year 2 | Scenario, Forecast | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations				35,186,000
CECONY | Electric | Year 3
Public Utilities, General Disclosures [Line Items]
Base rate changes	$ 382,000				382,000
Amortizations to income of net regulatory (assets) and liabilities					(205,000)
Potential earnings adjustment mechanism incentives					79,000
Negative revenue adjustments					597,000
Average rate base					$ 29,362,000
Weighted average cost of capital (after-tax)					6.85%
Actual return on common equity, percent					9.36%
Cost of long-term debt	4.64%				4.64%
Deferral, annual maximum (not more than) (percent)					0.05%
CECONY | Electric | Year 3 | Protected Portion
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					$ 34,000
Actual net expenses amount					17,000
CECONY | Electric | Year 3 | Over Seven To Fifteen Years
Public Utilities, General Disclosures [Line Items]
Recovery of energy efficiency and savings program costs					457,000
Amount of cost recovery					281,000
CECONY | Electric | Year 3 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					$ 31,026,000
CECONY | Electric | Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes				329,000
Amortizations to income of net regulatory (assets) and liabilities				78,000
Potential earnings adjustment mechanism incentives				47,000
Negative revenue adjustments				742,000
Average rate base				$ 39,174,000
Weighted average cost of capital (after-tax)				7.10%
Cost of long-term debt				5.01%
Requested rate increase (decrease), amount				$ 421,000
Reflects regulatory liability amortization				55,000
CECONY | Electric | Year 3 | Scenario, Forecast | Protected Portion
Public Utilities, General Disclosures [Line Items]
Reflects regulatory liability amortization				22,000
CECONY | Electric | Year 3 | Scenario, Forecast | Unprotected Portion
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA				1,000
CECONY | Electric | Year 3 | Scenario, Forecast | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations				$ 38,624,000