Pension Benefits - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Pension liability	$ 174	$ 1,719
Investments value	524	459
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in regulatory liabilities	(741)
Charge to OCI	1
Noncurrent liabilities	337	311
Investments value	15,404	14,979	$ 18,504	$ 17,022
Accumulated benefit obligation	11,739	11,167	15,469
Estimated future employer contributions	11
Other Nonqualified Supplemental Defined Benefit Pension
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	349	306
CECONY
Defined Benefit Plan Disclosure [Line Items]
Pension liability	156	1,628
Investments value	502	439
CECONY | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in regulatory liabilities	(710)
Charge to OCI	2
Noncurrent liabilities	313	287
Investments value	14,674	14,248	17,566	$ 16,147
Accumulated benefit obligation	11,031	10,478	$ 14,504
Estimated future employer contributions	9
CECONY | Other Nonqualified Supplemental Defined Benefit Pension
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 323	$ 280