Pension Benefits - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Pension liability	$ 3,090	$ 759
Investments value	525	465
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Regulatory assets and liabilities for future income taxes, net	3,067
Charge to OCI	30
Noncurrent liabilities	459
Investments value	18,504	17,022	$ 15,608	$ 13,450
Accumulated benefit obligation	15,469	16,768	15,015
Estimated future employer contributions	29
Other Nonqualified Supplemental Defined Benefit Pension
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	386	414
CECONY
Defined Benefit Plan Disclosure [Line Items]
Pension liability	2,899	714
Investments value	499	439
CECONY | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Regulatory assets and liabilities for future income taxes, net	2,910
Charge to OCI	6
Noncurrent liabilities	381
Investments value	17,566	16,147	14,790	$ 12,744
Accumulated benefit obligation	14,504	15,676	$ 14,010
Estimated future employer contributions	20
CECONY | Other Nonqualified Supplemental Defined Benefit Pension
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 352	$ 377