Income Tax - Income Tax Reconciliation (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
STATUTORY TAX RATE
Federal	21.00%	21.00%	21.00%	21.00%
Changes in computed taxes resulting from:
State income tax, net of federal income taxes	5.00%	8.00%	5.00%	5.00%
Amortization of excess deferred federal income taxes	(7.00%)	(6.00%)	(8.00%)	(5.00%)
Cost of removal	1.00%	1.00%	2.00%	1.00%
Other plant-related items			(1.00%)	0.00%
Renewable energy credits			(1.00%)	(1.00%)
Allowance for uncollectible accounts, net of COVID-19 assistance	(1.00%)	(2.00%)
Changes in state apportionments, net of federal income taxes	0	0.01	0	(0.01)
Deferred unamortized ITC recognized on sale of subsidiary			0.00%	(4.00%)
Other	0.00%	2.00%	(1.00%)	0.00%
Effective tax rate	19.00%	21.00%	17.00%	16.00%
CECONY | Subsidiaries
STATUTORY TAX RATE
Federal	21.00%	21.00%	21.00%	21.00%
Changes in computed taxes resulting from:
State income tax, net of federal income taxes	5.00%	5.00%	5.00%	5.00%
Amortization of excess deferred federal income taxes	(7.00%)	(7.00%)	(9.00%)	(8.00%)
Cost of removal	1.00%	1.00%	2.00%	2.00%
Other plant-related items			0.00%	(1.00%)
Renewable energy credits			0.00%	0.00%
Allowance for uncollectible accounts, net of COVID-19 assistance	(1.00%)	(2.00%)
Changes in state apportionments, net of federal income taxes	0	0	0	0
Deferred unamortized ITC recognized on sale of subsidiary			0.00%	0.00%
Other	1.00%	1.00%	(1.00%)	0.00%
Effective tax rate	18.00%	17.00%	18.00%	19.00%