Regulatory Matters - Regulatory Assets (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024	Jan. 01, 2024	Jan. 01, 2022
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	$ 5,519.0	$ 5,523.0
Regulatory assets – current	112.0	141.0
Total Regulatory Assets	5,631.0	5,664.0
Energy efficiency and other clean energy programs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,702.0	1,675.0
Customer account deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,135.0	1,073.0
Environmental investigation and remediation costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,031.0	1,038.0
Revenue taxes
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	592.0	540.0
Legacy meters
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	398.0	413.0
Property tax reconciliation
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	108.0	131.0
Deferred storm costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	106.0	147.0
Deferred derivative losses - long term
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	105.0	106.0
MTA power reliability deferral
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	15.0	31.0
Unrecognized pension and other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	15.0	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	312.0	367.0
Deferred derivative losses - short term
Regulatory Assets [Line Items]
Regulatory assets – current	107.0	102.0
Recoverable energy costs
Regulatory Assets [Line Items]
Regulatory assets – current	5.0	39.0
CECONY
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	5,156.0	5,158.0
Regulatory assets – current	102.0	106.0
CECONY | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	5,156.0	5,158.0
Regulatory assets – current	102.0	106.0
Total Regulatory Assets	5,258.0	5,264.0
CECONY | Energy efficiency and other clean energy programs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,606.0	1,601.0
CECONY | Customer account deferrals | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,125.0	1,058.0
CECONY | Environmental investigation and remediation costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	944.0	952.0
CECONY | Revenue taxes | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	566.0	517.0
CECONY | Legacy meters | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	384.0	398.0
CECONY | Property tax reconciliation | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	108.0	131.0
CECONY | Deferred storm costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	24.0	53.0
CECONY | Deferred derivative losses - long term | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	93.0	94.0
CECONY | MTA power reliability deferral | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	15.0	31.0
CECONY | Unrecognized pension and other postretirement costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	9.0	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	282.0	321.0
CECONY | Deferred derivative losses - short term | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – current	97.0	92.0
CECONY | Recoverable energy costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – current	5.0	14.0
CECONY | Arrears Relief Program Deferral
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	296.0	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