Related Party Transactions - Summary of Costs of Administrative and Other Services Provided and Received (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Related Party Transaction [Line Items]
Cost of services provided	$ 14,663	$ 15,670	$ 13,676
Cost of services received	12,332	13,046	10,850
CECONY
Related Party Transaction [Line Items]
Cost of services provided	13,476	13,268	11,716
Cost of services received	11,299	11,133	9,256
CECONY | Related Party
Related Party Transaction [Line Items]
Cost of services provided	146	135	137
Cost of services received	$ 82	$ 75	$ 68