Derivative Instruments and Hedging Activities - Hedged Volume of Derivative Transactions (Details)	Mar. 31, 2024 gal MWh MW MMBTU
Electric Energy (MWh)
Derivatives, Fair Value [Line Items]
Notional amount | MWh	31,374,625
Capacity (MW)
Derivatives, Fair Value [Line Items]
Notional amount | MW	42,600
Natural Gas (Dt)
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	296,190,000
Refined Fuels (gallons)
Derivatives, Fair Value [Line Items]
Notional amount | gal	4,032,000
CECONY | Electric Energy (MWh) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MWh	28,801,875
CECONY | Capacity (MW) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MW	33,600
CECONY | Natural Gas (Dt) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	278,560,000
CECONY | Refined Fuels (gallons) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | gal	4,032,000