Related Party Transactions - Summary of Costs of Administrative and Other Services Provided and Received (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Related Party Transaction [Line Items]
Cost of services provided	$ 3,220	$ 2,944	$ 7,495	$ 7,347
Cost of services received	2,900	2,673	6,134	6,192
CECONY
Related Party Transaction [Line Items]
Cost of services provided	2,996	2,744	6,967	6,697
Cost of services received	2,682	2,482	5,663	5,626
CECONY | Related Party
Related Party Transaction [Line Items]
Cost of services provided	35	33	68	67
Cost of services received	$ 21	$ 21	$ 41	$ 40