Regulatory Matters - Summary of Utilities Rate Plans (CECONY-Electric) (Details) - USD ($)	1 Months Ended	12 Months Ended			36 Months Ended
	Nov. 30, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2025	Dec. 31, 2022	Dec. 31, 2019
Public Utilities, General Disclosures [Line Items]
Deferred regulatory liabilities		$ 3,000,000	$ 7,000,000	$ 41,000,000		$ 3,000,000	$ 17,000,000
Revenues		$ 15,670,000,000	13,676,000,000	12,246,000,000
NYSPSC
Public Utilities, General Disclosures [Line Items]
Percentage of total consolidated revenues		15.00%				15.00%
NYSPSC | Maximum
Public Utilities, General Disclosures [Line Items]
Percentage of total consolidated revenues		15.00%				15.00%
Percentage of debt to total consolidated debt						20.00%
CECONY
Public Utilities, General Disclosures [Line Items]
Revenues		$ 13,268,000,000	11,716,000,000	10,647,000,000
CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Retention of annual transmission congestion revenues						$ 75,000,000
Actual earnings adjustment mechanism incentives		33,000,000	64,000,000	34,000,000
Deferred regulatory liabilities		90,000,000	226,000,000	242,000,000		90,000,000
Negative revenue adjustments		3,000,000	0	5,000,000
Cost reconciliation, deferred net regulatory liabilities		138,000,000	191,000,000	288,000,000		138,000,000
Deferred regulatory asset (liability)		$ 1,800,000	3,200,000	4,100,000		$ 1,800,000
Authorized return on common equity (percent)						8.80%
Earnings sharing (percent)		9.30%				9.30%
Earnings sharing, threshold limit		$ 0	0	0
Earnings sharing, positive adjustment			$ 4,300,000
Common equity ratio (percent)		48.00%
Recovery or refund of energy costs, deferral period						10 years
Deferrals for property taxes limitation from rates (percent)						90.00%
Recovery deferral (percent)							80.00%
Maximum deferral (percent)		15.00%				15.00%
CECONY | Electric | Gas Leak Backlog, Leak Prone Pipe and Service Terminations
Public Utilities, General Disclosures [Line Items]
Revenues		$ 4,000,000
CECONY | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Retention of annual transmission congestion revenues					$ 75,000,000
Authorized return on common equity (percent)					9.25%
Earnings sharing (percent)					9.75%
Common equity ratio (percent)					48.00%
CECONY | Electric | NYSPSC
Public Utilities, General Disclosures [Line Items]
Actual return on common equity (percent)			8.81%
Amount of cost recovery	$ 43,000,000			$ 43,000,000
CECONY | Electric | Rate Plan for Year 1
Public Utilities, General Disclosures [Line Items]
Base rate changes		$ 113,000,000				$ 113,000,000
Amortizations to income of net regulatory (assets) and liabilities						267,000,000
Potential earnings adjustment mechanism incentives						69,000,000
Potential penalties (annually)						450,000,000
Average rate base						$ 21,660,000,000
Weighted average cost of capital (after-tax) (percent)						6.61%
Actual return on common equity (percent)						8.50%
Cost of long-term debt rate		4.63%				4.63%
Recovery of energy efficiency and savings program costs						$ 206,000,000
Deferral, annual maximum (not more than) (percent)						0.10%
CECONY | Electric | Rate Plan for Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes					$ 442,000,000
Amortizations to income of net regulatory (assets) and liabilities					104,000,000
Potential earnings adjustment mechanism incentives					70,000,000
Potential penalties (annually)					516,000,000
Average rate base					$ 26,095,000,000
Weighted average cost of capital (after-tax) (percent)					6.75%
Cost of long-term debt rate					4.46%
Deferral, annual maximum (not more than) (percent)					0.10%
CECONY | Electric | Rate Plan for Year 1 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						$ 24,491,000,000
CECONY | Electric | Rate Plan for Year 1 | Electric average excluding AMI | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					$ 27,847,000,000
CECONY | Electric | Rate Plan for Year 1 | Advanced metering infrastructure (AMI)
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						572,000,000
CECONY | Electric | Rate Plan for Year 1 | Advanced metering infrastructure (AMI) | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					744,000,000
CECONY | Electric | Rate Plan for Year 1 | Customer Service Systems (CSS) | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					11,000,000
CECONY | Electric | Rate Plan for Year 2
Public Utilities, General Disclosures [Line Items]
Base rate changes		$ 370,000,000				370,000,000
Amortizations to income of net regulatory (assets) and liabilities						269,000,000
Potential earnings adjustment mechanism incentives						74,000,000
Potential penalties (annually)						461,000,000
Average rate base						$ 22,783,000,000
Weighted average cost of capital (after-tax) (percent)						6.61%
Actual return on common equity (percent)						8.03%
Cost of long-term debt rate		4.63%				4.63%
Recovery of energy efficiency and savings program costs						$ 245,000,000
Deferral, annual maximum (not more than) (percent)						0.075%
CECONY | Electric | Rate Plan for Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes					518,000,000
Amortizations to income of net regulatory (assets) and liabilities					49,000,000
Potential earnings adjustment mechanism incentives					75,000,000
Potential penalties (annually)					557,000,000
Average rate base					$ 27,925,000,000
Weighted average cost of capital (after-tax) (percent)					6.79%
Cost of long-term debt rate					4.54%
Deferral, annual maximum (not more than) (percent)					0.05%
CECONY | Electric | Rate Plan for Year 2 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						$ 25,092,000,000
CECONY | Electric | Rate Plan for Year 2 | Electric average excluding AMI | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					$ 29,884,000,000
CECONY | Electric | Rate Plan for Year 2 | Advanced metering infrastructure (AMI)
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						740,000,000
CECONY | Electric | Rate Plan for Year 3
Public Utilities, General Disclosures [Line Items]
Base rate changes		$ 326,000,000				326,000,000
Amortizations to income of net regulatory (assets) and liabilities						272,000,000
Potential earnings adjustment mechanism incentives						79,000,000
Potential penalties (annually)						476,000,000
Average rate base						$ 23,926,000,000
Weighted average cost of capital (after-tax) (percent)						6.61%
Actual return on common equity (percent)						8.41%
Cost of long-term debt rate		4.63%				4.63%
Recovery of energy efficiency and savings program costs						$ 251,000,000
Deferral, annual maximum (not more than) (percent)						0.05%
CECONY | Electric | Rate Plan for Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes					382,000,000
Amortizations to income of net regulatory (assets) and liabilities					(205,000,000)
Potential earnings adjustment mechanism incentives					79,000,000
Potential penalties (annually)					597,000,000
Average rate base					$ 29,362,000,000
Weighted average cost of capital (after-tax) (percent)					6.85%
Cost of long-term debt rate					4.64%
Deferral, annual maximum (not more than) (percent)					0.05%
CECONY | Electric | Rate Plan for Year 3 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						$ 25,708,000,000
CECONY | Electric | Rate Plan for Year 3 | Electric average excluding AMI | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					$ 31,026,000,000
CECONY | Electric | Rate Plan for Year 3 | Advanced metering infrastructure (AMI)
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						806,000,000
Annually | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA						126,000,000
Annually | CECONY | Electric | Deferred Project Costs
Public Utilities, General Disclosures [Line Items]
Amortizations to income of net regulatory (assets) and liabilities						48,000,000
Annually | CECONY | Electric | Deferred Project Costs | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Amortizations to income of net regulatory (assets) and liabilities					31,000,000
Annually | CECONY | Electric | Rate Plan for Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA					128,000,000
Annually | CECONY | Electric | Rate Plan for Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA					128,000,000
Over Five Years | CECONY | Electric | Deferred Project Costs
Public Utilities, General Disclosures [Line Items]
Amortizations to income of net regulatory (assets) and liabilities						238,000,000
Over Three Years | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA						377,000,000
Over Three Years | CECONY | Electric | Deferred Project Costs | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Amortizations to income of net regulatory (assets) and liabilities					93,000,000
Over Two Years | CECONY | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA					256,000,000
Over Seven To Fifteen Years | CECONY | Electric | Rate Plan for Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Amount of cost recovery					244,000,000
Requested rate increase (decrease), amount					457,000,000
Over Seven To Fifteen Years | CECONY | Electric | Rate Plan for Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Amount of cost recovery					237,000,000
Requested rate increase (decrease), amount					457,000,000
Over Seven To Fifteen Years | CECONY | Electric | Rate Plan for Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Amount of cost recovery					281,000,000
Requested rate increase (decrease), amount					457,000,000
Protected Portion | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA						1,663,000,000
Protected Portion | CECONY | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					1,512,000,000
Protected Portion | CECONY | Electric | Rate Plan for Year 1
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA						49,000,000
Protected Portion | CECONY | Electric | Rate Plan for Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					34,000,000
Protected Portion | CECONY | Electric | Rate Plan for Year 2
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA						50,000,000
Protected Portion | CECONY | Electric | Rate Plan for Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					63,000,000
Protected Portion | CECONY | Electric | Rate Plan for Year 3
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA						53,000,000
Protected Portion | CECONY | Electric | Rate Plan for Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					34,000,000
Unprotected Portion | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA						$ 784,000,000
TCJA of 2017 regulatory liabilities, income tax benefit, amortization period						5 years
Unprotected Portion | Annually | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA						$ 157,000,000
Unprotected Portion | Annually | CECONY | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					153,000,000
Unprotected Portion | Over Two Years | CECONY | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					$ 306,000,000