Current Expected Credit Losses - Schedule of Major Portfolio Segment Type (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Reserve adjustments	$ 5	$ 169	$ 78
Accounts receivable - customers
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance at January 1,	317	148
Recoveries	17	14
Write-offs	(103)	(91)
Reserve adjustments	91	246
Ending Balance December 31,	322	317	148
Other receivables
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance at January 1,	22	7
Recoveries	0	1
Write-offs	(6)	(2)
Reserve adjustments	(6)	16
Ending Balance December 31,	10	22	7
CECONY
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Reserve adjustments	10	166	74
CECONY | Accounts receivable - customers | Subsidiaries
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance at January 1,	304	138
Recoveries	16	12
Write-offs	(94)	(86)
Reserve adjustments	88	240
Ending Balance December 31,	314	304	138
CECONY | Other receivables | Subsidiaries
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance at January 1,	19	4
Recoveries	0	1
Write-offs	(4)	(1)
Reserve adjustments	(8)	15
Ending Balance December 31,	$ 7	$ 19	$ 4