Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance as of January 1,	$ 500	$ 577
ARO held for sale	0	(77)
Changes in estimated cash flows	76	44
Accretion expense	17	18
Liabilities settled	(71)	(62)
Ending Balance as of December 31,	522	500
Asset retirement obligation, period increase (decrease)	(77)	(78)
Disposal Group, Held-for-sale, Not Discontinued Operations | Clean Energy Businesses
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Disposal group, including discontinued operation, asset retirement obligations	3	77
CECONY
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance as of January 1,	499	504
ARO held for sale	0	0
Changes in estimated cash flows	75	43
Accretion expense	17	14
Liabilities settled	(71)	(62)
Ending Balance as of December 31,	520	499
Asset retirement obligation, period increase (decrease)	$ (77)	$ (77)