Derivative Instruments and Hedging Activities - Hedged Volume of Derivative Transactions (Details)	Mar. 31, 2023 gal MWh MW MMBTU
Electric Energy (MWh)
Derivatives, Fair Value [Line Items]
Notional amount | MWh	30,093,325
Capacity (MW)
Derivatives, Fair Value [Line Items]
Notional amount | MW	48,600
Natural Gas (Dt)
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	273,950,000
Refined Fuels (gallons)
Derivatives, Fair Value [Line Items]
Notional amount | gal	4,116,000
CECONY | Electric Energy (MWh) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MWh	28,352,725
CECONY | Capacity (MW) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MW	41,400
CECONY | Natural Gas (Dt) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	260,910,000
CECONY | Refined Fuels (gallons) | Subsidiaries
Derivatives, Fair Value [Line Items]
Notional amount | gal	4,116,000