Regulatory Matters - COVID-19 Regulatory Matters (Details) $ in Millions	1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended		13 Months Ended	25 Months Ended	34 Months Ended	43 Months Ended	45 Months Ended
	Jan. 31, 2023	Jan. 31, 2021	Sep. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2021 USD ($)	Nov. 30, 2021 USD ($)	Jan. 01, 2021 USD ($)
Public Utilities, General Disclosures [Line Items]
Reserve adjustments					$ (46.0)	$ (12.0)
CECONY
Public Utilities, General Disclosures [Line Items]
Reserve adjustments					(45.0)	$ (7.0)
Deferred costs			$ 3.0		3.0							$ 3.0	$ 3.0
CECONY | Subsidiaries | COVID-19 Arrears Assistance Program
Public Utilities, General Disclosures [Line Items]
Credits issued from government assistance			4.9		348.4			$ 359.9
Eligible credit recovery period (in years)	10 years
O&R | Subsidiaries | COVID-19 Arrears Assistance Program
Public Utilities, General Disclosures [Line Items]
Credits issued from government assistance			$ 0.2		$ 2.8			6.1
Eligible credit recovery period (in years)	1 year
COVID-19
Public Utilities, General Disclosures [Line Items]
Deferred costs														$ 0.3
COVID-19 | Consolidated Edison Company of New York, Inc. And Orange And Rockland | Subsidiaries
Public Utilities, General Disclosures [Line Items]
Reserve for customer arrearages															$ 7.0
COVID-19 | Consolidated Edison Company of New York, Inc. And Orange And Rockland | Electric and Gas Transmission Projects | Subsidiaries
Public Utilities, General Disclosures [Line Items]
Write off										$ 11.0	$ 46.0
COVID-19 | CECONY | Subsidiaries
Public Utilities, General Disclosures [Line Items]
Reserve for customer arrearages																$ 7.0
COVID-19 | CECONY | Electric and Gas Transmission Projects | Subsidiaries
Public Utilities, General Disclosures [Line Items]
Percent of total customer bill impact per commodity (no more than)			0.005		0.005							0.005	0.005
Reserve adjustments													$ 205.0
Write off												$ 55.0
Credits issued from government assistance				$ 164.5
Tax credit					$ 7.6			80.0
COVID-19 | CECONY | Electric and Gas Transmission Projects | Subsidiaries | COVID-19 Arrears Phase 1 Assistance Program
Public Utilities, General Disclosures [Line Items]
Credits issued from government assistance				108.4	13.2
COVID-19 | CECONY | Electric and Gas Transmission Projects | Subsidiaries | COVID-19 Arrears Phase 2 Assistance Program
Public Utilities, General Disclosures [Line Items]
Credits issued from government assistance					327.6
COVID-19 | CECONY | Gas | Subsidiaries
Public Utilities, General Disclosures [Line Items]
Late payment charges and fees									$ 7.0
COVID-19 | CECONY | Gas | Subsidiaries | Year 1
Public Utilities, General Disclosures [Line Items]
Annual cap for late payment charges and write-offs					14.8
COVID-19 | CECONY | Gas | Subsidiaries | Year 2
Public Utilities, General Disclosures [Line Items]
Annual cap for late payment charges and write-offs					15.9
COVID-19 | CECONY | Gas | Subsidiaries | Year 3
Public Utilities, General Disclosures [Line Items]
Annual cap for late payment charges and write-offs					16.8
COVID-19 | CECONY | Gas | Subsidiaries | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Late payment charges and fees							$ 4.0
COVID-19 | CECONY | Electric | Subsidiaries
Public Utilities, General Disclosures [Line Items]
Late payment charges and fees									$ 43.0
COVID-19 | CECONY | Electric | Subsidiaries | Year 1
Public Utilities, General Disclosures [Line Items]
Annual cap for late payment charges and write-offs					57.3
COVID-19 | CECONY | Electric | Subsidiaries | Year 2
Public Utilities, General Disclosures [Line Items]
Annual cap for late payment charges and write-offs					60.3
COVID-19 | CECONY | Electric | Subsidiaries | Year 3
Public Utilities, General Disclosures [Line Items]
Annual cap for late payment charges and write-offs					$ 62.6
COVID-19 | CECONY | Electric | Subsidiaries | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Late payment charges and fees							$ 19.0
COVID-19 | O&R | Electric and Gas Transmission Projects | Subsidiaries
Public Utilities, General Disclosures [Line Items]
Full recovery via surcharge limitation (in basis points)					0.0005
Credits issued from government assistance				1.6
Tax credit					$ 0.6			$ 1.3
COVID-19 | O&R | Electric and Gas Transmission Projects | Subsidiaries | COVID-19 Arrears Phase 1 Assistance Program
Public Utilities, General Disclosures [Line Items]
Credits issued from government assistance				$ 3.2	0.1
COVID-19 | O&R | Electric and Gas Transmission Projects | Subsidiaries | COVID-19 Arrears Phase 2 Assistance Program
Public Utilities, General Disclosures [Line Items]
Credits issued from government assistance					$ 2.1
COVID-19 | O&R | Gas | Subsidiaries
Public Utilities, General Disclosures [Line Items]
Reserve adjustments													$ 2.0
Write off												$ 2.0
Summer Cooling Credit Program | Residential Customers | COVID-19 | CECONY | Subsidiaries
Public Utilities, General Disclosures [Line Items]
Expected deferred revenue																	$ 63.4
Cost of the program, recovery period		5 years