Environmental Matters - Accrued Liabilities and Regulatory Assets (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Site Contingency [Line Items]
Accrued Liabilities	$ 1,118	$ 997
Regulatory assets	4,888	4,279
Manufactured gas plant sites
Site Contingency [Line Items]
Accrued Liabilities	1,016	876
Other Superfund Sites
Site Contingency [Line Items]
Accrued Liabilities	102	121
Superfund Sites
Site Contingency [Line Items]
Accrued Liabilities	1,118	997
Regulatory assets	1,105	991
CECONY
Site Contingency [Line Items]
Accrued Liabilities	1,026	903
CECONY | Manufactured gas plant sites
Site Contingency [Line Items]
Accrued Liabilities	924	782
CECONY | Other Superfund Sites
Site Contingency [Line Items]
Accrued Liabilities	102	121
CECONY | Superfund Sites
Site Contingency [Line Items]
Accrued Liabilities	1,026	903
Regulatory assets	$ 1,022	$ 906