Related Party Transactions - Summary of Costs of Administrative and Other Services Provided and Received (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Related Party Transaction [Line Items]
Total revenues	$ 3,872	$ 4,165	$ 11,219	$ 11,639
TOTAL OPERATING EXPENSES	3,149	3,276	9,340	9,565
CECONY
Related Party Transaction [Line Items]
Total revenues	3,590	3,549	10,287	9,972
TOTAL OPERATING EXPENSES	2,911	2,811	8,537	8,243
CECONY | Related Party
Related Party Transaction [Line Items]
Total revenues	39	35	105	101
TOTAL OPERATING EXPENSES	$ 21	$ 19	$ 61	$ 56