Related Party Transactions - Summary of Costs of Administrative and Other Services Provided and Received (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Related Party Transaction [Line Items]
Total revenues	$ 4,280	$ 4,403
Cost of services received	3,239	3,519
CECONY
Related Party Transaction [Line Items]
Total revenues	3,971	3,953
Cost of services received	2,982	3,144
CECONY | Related Party
Related Party Transaction [Line Items]
Total revenues	32	33
Cost of services received	$ 20	$ 19