Derivative Instruments and Hedging Activities - Hedged Volume of Derivative Transactions (Details)	Jun. 30, 2022 MMBTU MW gal MWh
Electric Energy (MWh)
Derivatives, Fair Value [Line Items]
Notional amount | MWh	25,403,485
Capacity (MW)
Derivatives, Fair Value [Line Items]
Notional amount | MW	36,075
Natural Gas (Dt)
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	251,449,055
Refined Fuels (gallons)
Derivatives, Fair Value [Line Items]
Notional amount | gal	1,680,000
CECONY | Electric Energy (MWh) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MWh	23,023,275
CECONY | Capacity (MW) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MW	23,025
CECONY | Natural Gas (Dt) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	234,190,000
CECONY | Refined Fuels (gallons) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | gal	1,680,000