Regulatory Matters - Summary of Utilities Rate Plans (CECONY-Gas) (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]
Revenues		$ 15,670,000,000	$ 13,676,000,000	$ 12,246,000,000
Deferred regulatory liabilities		3,000,000	7,000,000	41,000,000		$ 3,000,000	$ 17,000,000
CECONY
Public Utilities, General Disclosures [Line Items]
Revenues		13,268,000,000	11,716,000,000	10,647,000,000
CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Percentage of revenue reserve						15.00%
Other earnings incentives		8,000,000	26,000,000	3,000,000
Deferred regulatory liabilities		141,000,000	100,000,000	27,000,000		$ 141,000,000
Negative revenue adjustments		8,000,000	0	0
Cost reconciliation, deferred net regulatory liabilities		70,000,000	14,000,000	91,000,000		70,000,000
Deferred regulatory asset (liability)		10,800,000	(26,000,000)	$ (24,700,000)		$ 10,800,000
Authorized return on common equity (percent)						8.80%
Earnings sharing (percent)				9.30%
Earnings sharing, threshold limit		0	0	$ 0
CECONY | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Percentage of revenue reserve					15.00%
Earnings sharing (percent)					9.75%
Common equity ratio (percent)					48.00%
CECONY | Gas | Maximum
Public Utilities, General Disclosures [Line Items]
Amount of revenues retained		65,000,000				$ 65,000,000
CECONY | Gas | Maximum | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Amount of revenues retained					$ 65,000,000
CECONY | Gas | Gas Leak Backlog, Leak Prone Pipe and Service Terminations
Public Utilities, General Disclosures [Line Items]
Revenues		$ 9,000,000	$ 7,000,000	$ 13,000,000
CECONY | Gas | Service Termination
Public Utilities, General Disclosures [Line Items]
Incentives reversed						6,000,000
CECONY | Gas | Rate Plan for Year 1
Public Utilities, General Disclosures [Line Items]
Base rate changes						84,000,000
Amortizations to income of net regulatory (assets) and liabilities						45,000,000
Potential incentives if performance targets are met						20,000,000
Potential penalties (annually)						81,000,000
Average rate base						$ 7,171,000,000
Weighted average cost of capital (after-tax) (percent)						6.61%
Actual return on common equity (percent)						8.40%
Cost of long-term debt rate		4.63%				4.63%
CECONY | Gas | Rate Plan for Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes					217,000,000
Amortizations to income of net regulatory (assets) and liabilities					31,000,000
Potential incentives if performance targets are met					18,000,000
Potential penalties (annually)					107,000,000
Average rate base					$ 9,647,000,000
Weighted average cost of capital (after-tax) (percent)					6.75%
Authorized return on common equity (percent)					9.25%
Cost of long-term debt rate					4.46%
CECONY | Gas | Rate Plan for Year 1 | Gas average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						$ 8,108,000,000
CECONY | Gas | Rate Plan for Year 1 | Gas average excluding AMI | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					$ 10,466,000,000
CECONY | Gas | Rate Plan for Year 1 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						142,000,000
CECONY | Gas | Rate Plan for Year 1 | AMI | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					234,000,000
CECONY | Gas | Rate Plan for Year 1 | Customer Service Systems (CSS) | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					2,000,000
CECONY | Gas | Rate Plan for Year 2
Public Utilities, General Disclosures [Line Items]
Base rate changes						122,000,000
Amortizations to income of net regulatory (assets) and liabilities						43,000,000
Potential incentives if performance targets are met						22,000,000
Potential penalties (annually)						88,000,000
Average rate base						$ 7,911,000,000
Weighted average cost of capital (after-tax) (percent)						6.61%
Actual return on common equity (percent)						8.48%
Cost of long-term debt rate		4.63%				4.63%
CECONY | Gas | Rate Plan for Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes					173,000,000
Amortizations to income of net regulatory (assets) and liabilities					24,000,000
Potential incentives if performance targets are met					20,000,000
Potential penalties (annually)					119,000,000
Average rate base					$ 10,428,000,000
Weighted average cost of capital (after-tax) (percent)					6.79%
Cost of long-term debt rate					4.54%
CECONY | Gas | Rate Plan for Year 2 | Gas average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						$ 8,808,000,000
CECONY | Gas | Rate Plan for Year 2 | Gas average excluding AMI | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					$ 11,442,000,000
CECONY | Gas | Rate Plan for Year 2 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						183,000,000
CECONY | Gas | Rate Plan for Year 3
Public Utilities, General Disclosures [Line Items]
Base rate changes						167,000,000
Amortizations to income of net regulatory (assets) and liabilities						10,000,000
Potential incentives if performance targets are met						25,000,000
Potential penalties (annually)						96,000,000
Average rate base						$ 8,622,000,000
Weighted average cost of capital (after-tax) (percent)						6.61%
Actual return on common equity (percent)						8.93%
Cost of long-term debt rate		4.63%				4.63%
CECONY | Gas | Rate Plan for Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes					122,000,000
Amortizations to income of net regulatory (assets) and liabilities					(11,000,000)
Potential incentives if performance targets are met					21,000,000
Potential penalties (annually)					130,000,000
Average rate base					$ 11,063,000,000
Weighted average cost of capital (after-tax) (percent)					6.85%
Cost of long-term debt rate					4.64%
CECONY | Gas | Rate Plan for Year 3 | Gas average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						$ 9,510,000,000
CECONY | Gas | Rate Plan for Year 3 | Gas average excluding AMI | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					$ 12,142,000,000
CECONY | Gas | Rate Plan for Year 3 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						$ 211,000,000
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%
NYSPSC | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Actual return on common equity (percent)				8.56%
Amount of cost recovery	$ 7,000,000			$ 7,000,000
Annually | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA						$ 32,000,000
Annually | CECONY | Gas | Rate Plan for Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA					16,000,000
Annually | CECONY | Gas | Rate Plan for Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA					16,000,000
Over Ten Years | CECONY | Gas | Rate Plan for Year 1
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount						47,000,000
Amount of cost recovery						30,000,000
Over Ten Years | CECONY | Gas | Rate Plan for Year 2
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount						176,000,000
Amount of cost recovery						37,000,000
Over Ten Years | CECONY | Gas | Rate Plan for Year 3
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount						170,000,000
Amount of cost recovery						40,000,000
Over Two Years | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA						63,000,000
Over Two Years | CECONY | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA					32,000,000
Over Fifteen Years | CECONY | Gas | Rate Plan for Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount					187,000,000
Amount of cost recovery					45,000,000
Over Fifteen Years | CECONY | Gas | Rate Plan for Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount					187,000,000
Amount of cost recovery					78,000,000
Over Fifteen Years | CECONY | Gas | Rate Plan for Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount					187,000,000
Amount of cost recovery					62,000,000
Protected Portion | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA						725,000,000
Protected Portion | CECONY | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					679,000,000
Protected Portion | CECONY | Gas | Rate Plan for Year 1
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA						14,000,000
Protected Portion | CECONY | Gas | Rate Plan for Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					9,000,000
Protected Portion | CECONY | Gas | Rate Plan for Year 2
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA						14,000,000
Protected Portion | CECONY | Gas | Rate Plan for Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					10,000,000
Protected Portion | CECONY | Gas | Rate Plan for Year 3
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA						12,000,000
Protected Portion | CECONY | Gas | Rate Plan for Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					10,000,000
Unprotected Portion | Annually | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA						21,000,000
Unprotected Portion | Annually | CECONY | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					21,000,000
Unprotected Portion | Over Two Years | CECONY | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA					$ 42,000,000
Unprotected Portion | Over Five Years | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA						$ 107,000,000