Regulatory Matters - Summary of Utilities Rate Plans (CECONY-Gas) (Details) - USD ($)	1 Months Ended					12 Months Ended					36 Months Ended
	Jan. 31, 2025	Jan. 31, 2024	Jan. 31, 2022	Nov. 30, 2021	Dec. 31, 2016	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2022	Dec. 31, 2019	Dec. 31, 2016	Dec. 31, 2024	Dec. 31, 2023
Public Utilities, General Disclosures [Line Items]
Revenues						$ 13,676,000,000	$ 12,246,000,000	$ 12,574,000,000
Deferred revenues						7,000,000	41,000,000	17,000,000	$ 20,000,000			$ 17,000,000
CECONY
Public Utilities, General Disclosures [Line Items]
Revenues						11,716,000,000	10,647,000,000	10,821,000,000
CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Percentage of revenue reserve												15.00%
Other earnings incentives						26,000,000	3,000,000	7,000,000	6,000,000	$ 7,000,000
Deferred revenues						100,000,000	27,000,000	10,000,000	12,000,000	3,000,000		$ 10,000,000
Negative revenue adjustments						0	0	0	4,000,000	5,000,000
Cost reconciliation, deferred net regulatory liabilities						14,000,000	91,000,000	18,000,000	44,000,000	2,000,000		18,000,000
Deferred regulatory asset (liability)						(26,000,000)	(24,700,000)	$ (1,700,000)	(2,200,000)	(2,200,000)		$ (1,700,000)
Earnings sharing (percent)								9.50%				9.50%
Earnings sharing, threshold limit						0	0	$ 0	0	0
Common equity ratio, percentage												48.00%
Increase in gas base rate due to expiration of temporary credit under the prior rate plan					$ 41,000,000
CECONY | Gas | Maximum
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						$ 7,000,000	13,000,000	9,000,000	5,000,000
CECONY | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Percentage of revenue reserve											15.00%
Earnings sharing (percent)														9.30%
Common equity ratio, percentage											48.00%
CECONY | Gas | Scenario, Forecast | Maximum
Public Utilities, General Disclosures [Line Items]
Amount of revenues retained															$ 65,000,000
CECONY | Gas | Year 1
Public Utilities, General Disclosures [Line Items]
Base rate changes												$ (5,000,000)
Utilities operating expense, depreciation and amortization												39,000,000
Potential incentives if performance targets are met												7,000,000
Potential penalties (annually)												68,000,000
Average rate base												$ 4,841,000,000
Weighted average cost of capital (after-tax) (percent)												6.82%
Authorized return on common equity (percent)												9.00%
Actual return on common equity (percent)												9.22%
Cost of long-term debt rate						4.93%
CECONY | Gas | Year 1 | Gas average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations												$ 5,844,000,000
CECONY | Gas | Year 1 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations												27,000,000
CECONY | Gas | Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes											$ 84,000,000
Utilities operating expense, depreciation and amortization											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%
Authorized return on common equity (percent)											8.80%
Actual return on common equity (percent)											8.40%
Cost of long-term debt rate											4.63%
CECONY | Gas | Year 1 | Scenario, Forecast | Gas average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations											$ 8,108,000,000
CECONY | Gas | Year 1 | Scenario, Forecast | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations											142,000,000
CECONY | Gas | Year 2
Public Utilities, General Disclosures [Line Items]
Base rate changes												92,000,000
Utilities operating expense, depreciation and amortization												37,000,000
Potential incentives if performance targets are met												8,000,000
Potential penalties (annually)												63,000,000
Average rate base												$ 5,395,000,000
Weighted average cost of capital (after-tax) (percent)												6.80%
Actual return on common equity (percent)												9.04%
Cost of long-term debt rate						4.88%
CECONY | Gas | Year 2 | Gas average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations												$ 6,512,000,000
CECONY | Gas | Year 2 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations												57,000,000
CECONY | Gas | Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes											122,000,000
Utilities operating expense, depreciation and amortization											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
Actual return on common equity (percent)											8.48%
CECONY | Gas | Year 2 | Scenario, Forecast | Gas average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations											$ 8,808,000,000
CECONY | Gas | Year 2 | Scenario, Forecast | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations											183,000,000
CECONY | Gas | Year 3
Public Utilities, General Disclosures [Line Items]
Base rate changes												90,000,000
Utilities operating expense, depreciation and amortization												36,000,000
Potential incentives if performance targets are met												8,000,000
Potential penalties (annually)												70,000,000
Average rate base												$ 6,005,000,000
Weighted average cost of capital (after-tax) (percent)												6.73%
Actual return on common equity (percent)												8.72%
Cost of long-term debt rate						4.74%
CECONY | Gas | Year 3 | Gas average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations												$ 7,177,000,000
CECONY | Gas | Year 3 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations												100,000,000
CECONY | Gas | Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes											167,000,000
Utilities operating expense, depreciation and amortization											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
CECONY | Gas | Year 3 | Scenario, Forecast | Gas average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations											9,510,000,000
CECONY | Gas | Year 3 | Scenario, Forecast | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations											$ 211,000,000
CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Other earnings incentives								5,000,000	5,000,000	5,000,000
Deferred revenues						$ 226,000,000	242,000,000	169,000,000	(6,000,000)	45,000,000		169,000,000
Negative revenue adjustments						0	5,000,000	15,000,000	0	0
Cost reconciliation, deferred net regulatory liabilities						191,000,000	288,000,000	10,000,000	189,000,000	35,000,000		10,000,000
Deferred regulatory asset (liability)						$ 3,200,000	4,100,000	(11,800,000)	$ (400,000)	400,000		$ (11,800,000)
Earnings sharing, threshold limit							$ 0	$ 0		$ 0
Common equity ratio, percentage												48.00%
Increase in gas base rate due to expiration of temporary credit under the prior rate plan					$ 48,000,000
CECONY | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Authorized return on common equity (percent)											8.80%
Earnings sharing (percent)														9.30%
Common equity ratio, percentage											48.00%
CECONY | Electric | Year 1
Public Utilities, General Disclosures [Line Items]
Utilities operating expense, depreciation and amortization												$ 84,000,000
Potential incentives if performance targets are met												28,000,000
Average rate base												$ 18,902,000,000
Weighted average cost of capital (after-tax) (percent)												6.82%
Authorized return on common equity (percent)												9.00%
Actual return on common equity (percent)												9.30%
Earnings sharing (percent)						9.50%
Cost of long-term debt rate						4.93%
Deferral, annual maximum (not more than) (percent)													10.00%
Recovery of energy efficiency and savings program costs												$ 20,500,000
CECONY | Electric | Year 1 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)												376,000,000
CECONY | Electric | Year 1 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations												126,000,000
CECONY | Electric | Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Utilities operating expense, depreciation and amortization											$ 267,000,000
Potential incentives if performance targets are met											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%
Amount of cost recovery											$ 206,000,000
CECONY | Electric | Year 1 | Scenario, Forecast | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations											572,000,000
CECONY | Electric | Year 2
Public Utilities, General Disclosures [Line Items]
Utilities operating expense, depreciation and amortization												83,000,000
Potential incentives if performance targets are met												47,000,000
Average rate base												$ 19,530,000,000
Weighted average cost of capital (after-tax) (percent)												6.80%
Actual return on common equity (percent)												9.36%
Cost of long-term debt rate						4.88%
Deferral, annual maximum (not more than) (percent)													7.50%
Recovery of energy efficiency and savings program costs												$ 49,000,000
CECONY | Electric | Year 2 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)												341,000,000
CECONY | Electric | Year 2 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations												257,000,000
CECONY | Electric | Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Utilities operating expense, depreciation and amortization											269,000,000
Potential incentives if performance targets are met											74,000,000
Potential penalties (annually)											461,000,000
Average rate base											$ 22,783,000,000
Actual return on common equity (percent)											8.03%
Amount of cost recovery											$ 245,000,000
CECONY | Electric | Year 2 | Scenario, Forecast | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations											740,000,000
CECONY | Electric | Year 3
Public Utilities, General Disclosures [Line Items]
Utilities operating expense, depreciation and amortization												69,000,000
Potential incentives if performance targets are met												64,000,000
Average rate base												$ 20,277,000,000
Weighted average cost of capital (after-tax) (percent)												6.73%
Actual return on common equity (percent)												8.82%
Cost of long-term debt rate						4.74%
Deferral, annual maximum (not more than) (percent)													5.00%
Recovery of energy efficiency and savings program costs												$ 107,500,000
CECONY | Electric | Year 3 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)												352,000,000
CECONY | Electric | Year 3 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations												$ 415,000,000
CECONY | Electric | Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Utilities operating expense, depreciation and amortization											272,000,000
Potential incentives if performance targets are met											79,000,000
Potential penalties (annually)											476,000,000
Average rate base											23,926,000,000
Amount of cost recovery											251,000,000
CECONY | Electric | Year 3 | Scenario, Forecast | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations											806,000,000
NYSPSC
Public Utilities, General Disclosures [Line Items]
Percentage of total consolidated revenues						15.00%
NYSPSC | Maximum
Public Utilities, General Disclosures [Line Items]
Percentage of total consolidated revenues						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		$ 4,000,000	$ 7,000,000
NYSPSC | CECONY | Gas | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Utilities operating expense, depreciation and amortization			$ 48,000,000
Requested rate increase (decrease), amount			$ 503,000,000
Return on common equity (percent)			10.00%
Common equity ratio			50.00%
NYSPSC | CECONY | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount	$ 218,000,000	$ 234,000,000
Return on common equity (percent)		10.00%
Common equity ratio		50.00%
NYSPSC | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Actual return on common equity (percent)							8.81%
Amount of cost recovery				$ 43,000,000		$ 19,000,000	$ 43,000,000
NYSPSC | CECONY | Electric | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount			$ 1,199,000,000
Return on common equity (percent)			10.00%
Common equity ratio			50.00%
NYSPSC | CECONY | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount	$ 608,000,000	$ 853,000,000
Return on common equity (percent)		10.00%
Common equity ratio		50.00%
Annually | CECONY | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA											32,000,000
Annually | CECONY | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA											126,000,000
Over Ten Years | CECONY | Gas | Year 1 | Scenario, Forecast
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 | Year 2 | Scenario, Forecast
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 | Year 3 | Scenario, Forecast
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 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA											63,000,000
Protected Portion | CECONY | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA											725,000,000
Protected Portion | CECONY | Gas | Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA											14,000,000
Protected Portion | CECONY | Gas | Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA											14,000,000
Protected Portion | CECONY | Gas | Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA											12,000,000
Protected Portion | CECONY | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA											1,663,000,000
Protected Portion | CECONY | Electric | Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA											49,000,000
Protected Portion | CECONY | Electric | Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA											50,000,000
Protected Portion | CECONY | Electric | Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA											53,000,000
Unprotected Portion | CECONY | Electric | Scenario, Forecast
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 | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA											$ 21,000,000
Unprotected Portion | Annually | CECONY | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA											157,000,000
Unprotected Portion | Over Five Years | CECONY | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA											$ 107,000,000