Pension Benefits - Additional Information (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions	$ 22
Contributions	15
CECONY | Pension Benefits | Subsidiaries
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions	19
Contributions	13
CECONY | External Trust | Subsidiaries
Defined Benefit Plan Disclosure [Line Items]
Contributions	$ 10