Current Expected Credit Losses - Rollforward of Segment Type (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Reserve adjustments			$ (46)	$ (12)
Accounts receivable - customers
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	$ 275	$ 336	322	317
Recoveries	3	4	11	13
Write-offs	(43)	2	(135)	(62)
Reserve adjustments	41	(37)	78	37
Ending Balance	276	305	276	305
Other receivables
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	28	9	10	22
Recoveries	0	0	0	0
Write-offs	(4)	(2)	(5)	(5)
Reserve adjustments	7	2	26	(8)
Ending Balance	31	9	31	9
CECONY
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Reserve adjustments			(45)	(7)
CECONY | Accounts receivable - customers | Subsidiaries
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	266	324	314	304
Recoveries	3	4	10	12
Write-offs	(41)	4	(130)	(56)
Reserve adjustments	41	(35)	75	37
Ending Balance	269	297	269	297
CECONY | Other receivables | Subsidiaries
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	24	7	7	19
Recoveries	0	0	0	0
Write-offs	(3)	(1)	(3)	(3)
Reserve adjustments	6	1	23	(9)
Ending Balance	$ 27	$ 7	$ 27	$ 7