Regulatory Matters - Regulatory Assets (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	$ 3,974	$ 3,639
Regulatory assets – current	305	206
Total Regulatory Assets	4,279	3,845
Environmental remediation costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	991	938
System peak reduction and energy efficiency programs (h)
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	783	285
Revenue taxes
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	436	395
Pension and other postretirement benefits deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	279	496
COVID - 19 pandemic deferrals (f)
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	292	282
Deferred storm costs (c)
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	270	276
Property tax reconciliation (g)
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	121	202
Gas service line deferred costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	99	100
COVID - 19 arrears relief deferrals programs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	104	0
MTA power reliability deferral (b)
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	92	140
Unrecognized pension and other postretirement costs (a)
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	78	128
Brooklyn Queens demand management program
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	33	36
Deferred derivative losses - long term
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	31	51
Electric vehicle make ready (j)
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	33	8
Municipal infrastructure support costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	29	44
Meadowlands heater odorization project
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	27	29
Non-wire alternative projects
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	22	23
Legacy meters
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	20	2
Preferred stock redemption
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	19	20
Unamortized loss on reacquired debt
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	11	16
Recoverable Demonstration project costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	17	16
Gate station upgrade project
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	14	14
Other
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	173	138
Deferred derivative losses
Regulatory Assets [Line Items]
Regulatory assets – current	184	141
Recoverable energy costs
Regulatory Assets [Line Items]
Regulatory assets – current	121	65
CECONY
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	3,669	3,316
Regulatory assets – current	286	188
CECONY | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	3,669	3,316
Regulatory assets – current	286	188
Total Regulatory Assets	3,955	3,504
CECONY | Environmental remediation costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	906	860
CECONY | System peak reduction and energy efficiency programs (h) | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	780	284
CECONY | Revenue taxes | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	417	378
CECONY | Pension and other postretirement benefits deferrals | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	240	435
CECONY | COVID - 19 pandemic deferrals (f) | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	288	277
CECONY | Deferred storm costs (c) | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	173	158
CECONY | Property tax reconciliation (g) | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	121	202
CECONY | Gas service line deferred costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	99	100
CECONY | COVID - 19 arrears relief deferrals programs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	101	0
CECONY | MTA power reliability deferral (b) | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	92	140
CECONY | Unrecognized pension and other postretirement costs (a) | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	78	110
CECONY | Brooklyn Queens demand management program | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	33	36
CECONY | Deferred derivative losses - long term | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	26	45
CECONY | Electric vehicle make ready (j) | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	30	7
CECONY | Municipal infrastructure support costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	29	44
CECONY | Meadowlands heater odorization project | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	27	29
CECONY | Non-wire alternative projects | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	22	23
CECONY | Legacy meters | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	0	0
CECONY | Preferred stock redemption | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	19	20
CECONY | Unamortized loss on reacquired debt | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	10	14
CECONY | Recoverable Demonstration project costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	16	15
CECONY | Gate station upgrade project | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	14	14
CECONY | Other | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	148	125
CECONY | Deferred derivative losses | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – current	178	133
CECONY | Recoverable energy costs | Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – current	$ 108	$ 55