Environmental Matters - Accrued Liability for Asbestos Suits and Workers' Compensation Proceedings (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Site Contingency [Line Items]
Regulatory assets	$ 4,279	$ 3,845
Regulatory liabilities	6,401	4,566
Asbestos Suits
Site Contingency [Line Items]
Accrued liability	8	8
Regulatory assets	8	8
Workers' Compensation
Site Contingency [Line Items]
Accrued liability	61	65
Regulatory liabilities	$ 11	$ 8
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	59	62
Regulatory liabilities	$ 11	$ 8
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities	Accrued Liabilities