Capitalization - Carrying Amounts and Fair Values of Long-Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Unamortized debt expense	$ 205	$ 202
Carrying Amount
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	21,295	20,796
Fair Value
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	19,483	18,234
CECONY | Subsidiaries
Debt Instrument [Line Items]
Unamortized debt discount	197	195
CECONY | Carrying Amount | Subsidiaries
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	19,578	19,080
CECONY | Fair Value | Subsidiaries
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	$ 17,901	16,699
Clean Energy Businesses | Carrying Amount
Debt Instrument [Line Items]
Long-Term Debt (including current portion)		2,645
Clean Energy Businesses | Fair Value
Debt Instrument [Line Items]
Long-Term Debt (including current portion)		$ 2,489