Regulatory Matters - Schedule of Regulatory Assets Not Earning a Return (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Regulatory Assets [Line Items]
Regulatory assets not earning return	$ 1,975	$ 1,883
CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	1,858	1,753
Unrecognized pension and other postretirement costs (a)
Regulatory Assets [Line Items]
Regulatory assets not earning return	78	128
Unrecognized pension and other postretirement costs (a) | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	78	110
Environmental remediation costs
Regulatory Assets [Line Items]
Regulatory assets not earning return	987	928
Environmental remediation costs | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	903	850
Revenue taxes
Regulatory Assets [Line Items]
Regulatory assets not earning return	414	375
Revenue taxes | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	397	359
Deferred derivative losses - long term
Regulatory Assets [Line Items]
Regulatory assets not earning return	31	51
Deferred derivative losses - long term | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	26	45
COVID-19 deferral for uncollectible accounts receivable
Regulatory Assets [Line Items]
Regulatory assets not earning return	253	236
COVID-19 deferral for uncollectible accounts receivable | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	249	231
Other
Regulatory Assets [Line Items]
Regulatory assets not earning return	28	24
Other | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	27	24
Deferred derivative losses
Regulatory Assets [Line Items]
Regulatory assets not earning return	184	141
Deferred derivative losses | CECONY
Regulatory Assets [Line Items]
Regulatory assets not earning return	$ 178	$ 134