Regulatory Matters - Regulatory Assets (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024	Jan. 01, 2024	Jan. 01, 2022
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	$ 5,582.0	$ 5,523.0
Regulatory assets – current	207.0	141.0
Total Regulatory Assets	5,789.0	5,664.0
Energy efficiency and other clean energy programs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,680.0	1,656.0
Customer account deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,115.0	1,073.0
Environmental investigation and remediation costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,037.0	1,038.0
Revenue taxes
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	579.0	540.0
Legacy meters
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	405.0	413.0
Deferred derivative losses - long term
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	148.0	106.0
Deferred storm costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	128.0	147.0
Property tax reconciliation
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	122.0	131.0
MTA power reliability deferral
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	23.0	31.0
Gas service line deferred costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	12.0	18.0
Unrecognized pension and other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	9.0	0.0
Pension and other postretirement benefits deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	0.0	2.0
Other
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	324.0	368.0
Deferred derivative losses - short term
Regulatory Assets [Line Items]
Regulatory assets – current	207.0	102.0
Recoverable energy costs
Regulatory Assets [Line Items]
Regulatory assets – current	0.0	39.0
CECONY
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	5,210.0	5,158.0
Regulatory assets – current	190.0	106.0
CECONY | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	5,210.0	5,158.0
Regulatory assets – current	190.0	106.0
Total Regulatory Assets	5,400.0	5,264.0
CECONY | Energy efficiency and other clean energy programs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,603.0	1,598.0
CECONY | Customer account deferrals | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,103.0	1,058.0
CECONY | Environmental investigation and remediation costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	951.0	952.0
CECONY | Revenue taxes | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	554.0	517.0
CECONY | Legacy meters | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	391.0	398.0
CECONY | Deferred derivative losses - long term | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	133.0	94.0
CECONY | Deferred storm costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	39.0	53.0
CECONY | Property tax reconciliation | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	122.0	131.0
CECONY | MTA power reliability deferral | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	23.0	31.0
CECONY | Gas service line deferred costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	12.0	18.0
CECONY | Unrecognized pension and other postretirement costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	4.0	0.0
CECONY | Pension and other postretirement benefits deferrals | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	0.0	2.0
CECONY | Other | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	275.0	306.0
CECONY | Deferred derivative losses - short term | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – current	190.0	92.0
CECONY | Recoverable energy costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – current	0.0	14.0
CECONY | Arrears Relief Program Deferral
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	314.1	323.7
O&R | Arrears Relief Program Deferral
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	$ 1.4	$ 1.4
Consolidated Edison Company of New York, Inc. And Orange And Rockland | Legacy meters
Regulatory Assets [Line Items]
Cost of the program, recovery period (in years)			15 years	12 years