Derivative Instruments and Hedging Activities - Hedged Volume of Derivative Transactions (Details)	Jun. 30, 2024 gal MW MWh MMBTU
Electric Energy (MWh)
Derivatives, Fair Value [Line Items]
Notional amount | MWh	36,200,145
Capacity (MW)
Derivatives, Fair Value [Line Items]
Notional amount | MW	37,500
Natural Gas (Dt)
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	315,730,000
Refined Fuels (gallons)
Derivatives, Fair Value [Line Items]
Notional amount | gal	3,276,000
CECONY | Electric Energy (MWh) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MWh	32,810,675
CECONY | Capacity (MW) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MW	29,400
CECONY | Natural Gas (Dt) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	295,700,000
CECONY | Refined Fuels (gallons) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | gal	3,276,000