Regulatory Matters - Schedule of Regulatory Assets Not Earning a Return (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Regulatory Assets [Line Items]
Regulatory assets not earning return	$ 2,313	$ 2,347
Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	2,164	2,209
Environmental remediation costs
Regulatory Assets [Line Items]
Regulatory assets not earning return	1,100	1,105
Environmental remediation costs | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	1,017	1,022
Revenue taxes
Regulatory Assets [Line Items]
Regulatory assets not earning return	514	490
Revenue taxes | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	493	470
COVID-19 deferral for uncollectible accounts receivable
Regulatory Assets [Line Items]
Regulatory assets not earning return	365	291
COVID-19 deferral for uncollectible accounts receivable | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	354	288
Deferred derivative losses - short term
Regulatory Assets [Line Items]
Regulatory assets not earning return	147	269
Deferred derivative losses - short term | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	136	253
Deferred derivative losses - long term
Regulatory Assets [Line Items]
Regulatory assets not earning return	115	163
Deferred derivative losses - long term | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	104	148
Unrecognized pension and other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets not earning return	7	0
Unrecognized pension and other postretirement costs | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	7	0
Other
Regulatory Assets [Line Items]
Regulatory assets not earning return	65	29
Other | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	$ 53	$ 28