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, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2025	Dec. 31, 2022	Dec. 31, 2021
Public Utilities, General Disclosures [Line Items]
TOTAL OPERATING REVENUES		$ 15,256,000,000	$ 14,663,000,000	$ 15,670,000,000
Deferred regulatory liabilities		0	0	3,000,000	$ 7,000,000			$ 3,000,000	$ 7,000,000
CECONY
Public Utilities, General Disclosures [Line Items]
TOTAL OPERATING REVENUES		14,129,000,000	13,476,000,000	13,268,000,000
Cost reconciliation, deferred net regulatory liabilities		2,400,000
CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Percentage of revenue reserve								15.00%
Other earnings incentives		7,000,000	5,000,000	8,000,000	26,000,000	$ 3,000,000
Deferred regulatory liabilities		93,000,000	162,000,000	141,000,000	100,000,000	27,000,000		$ 141,000,000	100,000,000
Negative revenue adjustments		2,000,000	3,000,000	8,000,000
Cost reconciliation, deferred net regulatory liabilities		29,000,000	12,000,000	70,000,000	14,000,000	91,000,000		70,000,000	14,000,000
Deferred regulatory asset (liability)		(31,500,000)	(15,500,000)	$ 10,800,000	(26,000,000)	$ (24,700,000)		$ 10,800,000	(26,000,000)
Authorized return on common equity (percent)								8.80%
Earnings sharing (percent)				9.30%				9.30%
Earnings sharing, threshold limit		4,300,000	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]
TOTAL OPERATING REVENUES		$ 3,000,000	$ 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
Weighted average cost of capital (after-tax)								$ 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%
Requested rate increase (decrease), amount									10,400,000
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
Weighted average cost of capital (after-tax)							$ 9,647,000,000
Weighted average cost of capital (after-tax) (percent)							6.75%
Authorized return on common equity (percent)							9.25%
Actual return on common equity (percent)							9.00%
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]
Average rate base								$ 8,108,000,000
CECONY | Gas | Rate Plan for Year 1 | Gas average excluding AMI | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Average rate base							$ 10,466,000,000
CECONY | Gas | Rate Plan for Year 1 | AMI
Public Utilities, General Disclosures [Line Items]
Average rate base								142,000,000
CECONY | Gas | Rate Plan for Year 1 | AMI | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Average rate base							234,000,000
CECONY | Gas | Rate Plan for Year 1 | Customer Service Systems (CSS) | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Average rate base							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
Weighted average cost of capital (after-tax)								$ 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%
Requested rate increase (decrease), amount									10,400,000
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
Weighted average cost of capital (after-tax)							$ 10,428,000,000
Weighted average cost of capital (after-tax) (percent)							6.79%
Actual return on common equity (percent)							9.82%
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]
Average rate base								$ 8,808,000,000
CECONY | Gas | Rate Plan for Year 2 | Gas average excluding AMI | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Average rate base							$ 11,442,000,000
CECONY | Gas | Rate Plan for Year 2 | AMI
Public Utilities, General Disclosures [Line Items]
Average rate base								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
Weighted average cost of capital (after-tax)								$ 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%
Requested rate increase (decrease), amount									$ 10,400,000
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
Weighted average cost of capital (after-tax)							$ 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]
Average rate base								$ 9,510,000,000
CECONY | Gas | Rate Plan for Year 3 | Gas average excluding AMI | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Average rate base							$ 12,142,000,000
CECONY | Gas | Rate Plan for Year 3 | AMI
Public Utilities, General Disclosures [Line Items]
Average rate base								211,000,000
NYSPSC | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Actual return on common equity (percent)						8.56%
Amount of cost recovery	$ 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 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Shortfall in revenue							99,000,000
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