Fair Value Measurements - Schedule of Commodity Derivatives (Details) - Level 3 $ in Millions	Dec. 31, 2024 USD ($) $ / MWh $ / kW-month
CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	$ (6)
Electricity | Forward Capacity Prices
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	(16)
Electricity | Forward Capacity Prices | CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	$ (7)
Electricity | Forward Capacity Prices | Minimum | CECONY | Subsidiaries
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit) | $ / kW-month	0.73
Electricity | Forward Energy Prices | Minimum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit)	0.73
Electricity | Forward Energy Prices | Maximum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit)	7.14
Electricity | Forward Energy Prices | Maximum | CECONY | Subsidiaries
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit)	7.14
Electricity | Forward Energy Prices | Weighted Average
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit)	3.69
Electricity | Forward Energy Prices | Weighted Average | CECONY | Subsidiaries
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit)	3.75
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	$ 1
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves | CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	$ 1
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves | Minimum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit)	(0.20)
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves | Minimum | CECONY | Subsidiaries
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit)	(0.20)
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves | Maximum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit)	3.88
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves | Maximum | CECONY | Subsidiaries
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit)	3.88
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves | Weighted Average
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit)	1.85
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves | Weighted Average | CECONY | Subsidiaries
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit)	1.85
Total Con Edison - Commodity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	$ (15)