Environmental Matters - Accrued Liability for Asbestos Suits and Workers' Compensation Proceedings (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Site Contingency [Line Items]
Regulatory assets	$ 5,664	$ 4,888
Regulatory liabilities	5,546	5,473
Asbestos Suits
Site Contingency [Line Items]
Accrued liability	8	8
Regulatory assets	8	8
Workers' Compensation
Site Contingency [Line Items]
Accrued liability	53	56
Regulatory liabilities	$ 20	$ 17
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities	Accrued Liabilities
CECONY | Asbestos Suits
Site Contingency [Line Items]
Accrued liability	$ 7	$ 7
Regulatory assets	7	7
CECONY | Workers' Compensation
Site Contingency [Line Items]
Accrued liability	51	54
Regulatory liabilities	$ 20	$ 17
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities	Accrued Liabilities