Derivative Instruments and Hedging Activities - Hedged Volume of Derivative Transactions (Details)	Sep. 30, 2022 MW gal MWh MMBTU
Electric Energy (MWh)
Derivatives, Fair Value [Line Items]
Notional amount | MWh	29,387,725
Capacity (MW)
Derivatives, Fair Value [Line Items]
Notional amount | MW	36,037
Natural Gas (Dt)
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	289,274,503
Refined Fuels (gallons)
Derivatives, Fair Value [Line Items]
Notional amount | gal	672,000
CECONY | Electric Energy (MWh) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MWh	27,281,075
CECONY | Capacity (MW) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MW	22,350
CECONY | Natural Gas (Dt) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	272,830,000
CECONY | Refined Fuels (gallons) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | gal	672,000