Regulatory Matters - Regulatory Assets (Details) - USD ($) $ in Millions	Jun. 30, 2024	Jan. 01, 2024	Dec. 31, 2023	Jan. 01, 2022
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	$ 5,096		$ 4,607
Regulatory assets – current	167		281
Total Regulatory Assets	5,263		4,888
System peak reduction and energy efficiency programs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,129		1,095
Environmental remediation costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,100		1,105
COVID - 19 pandemic deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	853		789
Revenue taxes
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	505		476
Legacy meters
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	428		17
Deferred storm costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	175		206
Property tax reconciliation
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	126		169
Deferred derivative losses - long term
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	115		163
Electric vehicle make ready
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	100		73
MTA power reliability deferral
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	46		61
Gas service line deferred costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	29		43
Pension and other postretirement benefits deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	9		48
Unrecognized pension and other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	7		0
Other
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	474		362
Deferred derivative losses - short term
Regulatory Assets [Line Items]
Regulatory assets – current	147		269
Recoverable energy costs
Regulatory Assets [Line Items]
Regulatory assets – current	20		12
CECONY
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	4,777		4,314
Regulatory assets – current	145		254
CECONY | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	4,777		4,314
Regulatory assets – current	145		254
Total Regulatory Assets	4,922		4,568
CECONY | System peak reduction and energy efficiency programs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,102		1,075
CECONY | Environmental remediation costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,017		1,022
CECONY | COVID - 19 pandemic deferrals | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	839		782
CECONY | Revenue taxes | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	484		455
CECONY | Legacy meters | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	413		0
CECONY | Deferred storm costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	82		115
CECONY | Property tax reconciliation | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	126		169
CECONY | Deferred derivative losses - long term | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	104		148
CECONY | Electric vehicle make ready | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	91		68
CECONY | MTA power reliability deferral | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	46		61
CECONY | Gas service line deferred costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	29		43
CECONY | Pension and other postretirement benefits deferrals | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	8		39
CECONY | Unrecognized pension and other postretirement costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	7		0
CECONY | Other | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	429		337
CECONY | Deferred derivative losses - short term | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – current	137		253
CECONY | Recoverable energy costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – current	$ 8		$ 1
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