Current Expected Credit Losses - Rollforward of Segment Type (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Reserve adjustments			$ 74	$ (47)
Accounts receivable - customers
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	$ 394	$ 244	360	322
Recoveries	3	4	17	8
Write-offs	(29)	(44)	(95)	(91)
Reserve adjustments	66	71	152	36
Ending Balance	434	275	434	275
Other receivables
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	17	10	13	10
Recoveries	0	0	0	0
Write-offs	0	0	0	(1)
Reserve adjustments	8	18	12	19
Ending Balance	25	28	25	28
CECONY
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Reserve adjustments			66	(48)
CECONY | Accounts receivable - customers | Subsidiaries
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	383	236	353	314
Recoveries	3	3	14	7
Write-offs	(28)	(41)	(90)	(89)
Reserve adjustments	61	68	142	34
Ending Balance	419	266	419	266
CECONY | Other receivables | Subsidiaries
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	12	8	9	7
Recoveries	0	0	0	0
Write-offs	0	0	0	0
Reserve adjustments	9	16	12	17
Ending Balance	$ 21	$ 24	$ 21	$ 24