Summary of Significant Accounting Policies and Other Matters - Capitalized Cost of Utility Plant (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Public Utility, Property, Plant and Equipment [Line Items]
General	$ 4,205	$ 4,170
Held for future use	117	80
Construction work in progress	2,484	2,152
NET UTILITY PLANT	46,752	44,214
Electric Generation
Public Utility, Property, Plant and Equipment [Line Items]
Generation	534	559
Electric Transmission
Public Utility, Property, Plant and Equipment [Line Items]
Transmission	4,223	3,955
Electric Distribution
Public Utility, Property, Plant and Equipment [Line Items]
Distribution	23,345	22,418
General
Public Utility, Property, Plant and Equipment [Line Items]
General	113	87
Gas
Public Utility, Property, Plant and Equipment [Line Items]
Gas	11,326	10,473
Steam
Public Utility, Property, Plant and Equipment [Line Items]
Steam	1,962	1,924
General
Public Utility, Property, Plant and Equipment [Line Items]
General	2,648	2,566
CECONY
Public Utility, Property, Plant and Equipment [Line Items]
General	3,879	3,854
Held for future use	109	72
Construction work in progress	2,268	1,985
NET UTILITY PLANT	44,009	41,611
CECONY | Electric Generation
Public Utility, Property, Plant and Equipment [Line Items]
Generation	534	559
CECONY | Electric Transmission
Public Utility, Property, Plant and Equipment [Line Items]
Transmission	3,916	3,658
CECONY | Electric Distribution
Public Utility, Property, Plant and Equipment [Line Items]
Distribution	22,130	21,240
CECONY | General
Public Utility, Property, Plant and Equipment [Line Items]
General	113	87
CECONY | Gas
Public Utility, Property, Plant and Equipment [Line Items]
Gas	10,567	9,748
CECONY | Steam
Public Utility, Property, Plant and Equipment [Line Items]
Steam	1,962	1,924
CECONY | General
Public Utility, Property, Plant and Equipment [Line Items]
General	$ 2,410	$ 2,338