Regulatory Matters - Schedule of Regulatory Assets Not Earning a Return (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Regulatory Assets [Line Items]
Regulatory assets not earning return	$ 2,402	$ 2,347
CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	2,240	2,209
Environmental remediation costs
Regulatory Assets [Line Items]
Regulatory assets not earning return	1,037	1,105
Environmental remediation costs | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	942	1,022
Revenue taxes
Regulatory Assets [Line Items]
Regulatory assets not earning return	567	490
Revenue taxes | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	543	470
Deferred derivative losses - long term
Regulatory Assets [Line Items]
Regulatory assets not earning return	106	163
Deferred derivative losses - long term | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	94	148
UB deferral for uncollectible accounts receivable
Regulatory Assets [Line Items]
Regulatory assets not earning return	551	291
UB deferral for uncollectible accounts receivable | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	541	288
Other
Regulatory Assets [Line Items]
Regulatory assets not earning return	39	29
Other | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	28	28
Deferred derivative losses - short term
Regulatory Assets [Line Items]
Regulatory assets not earning return	102	269
Deferred derivative losses - short term | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	$ 92	$ 253