Income Tax - Income Tax Reconciliation (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
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 tax benefit	7.00%	5.00%	6.00%	4.00%
Amortization of excess deferred federal income taxes	(17.00%)	(41.00%)	(9.00%)	(14.00%)
Taxes attributable to non-controlling interest	0.00%	14.00%	1.00%	2.00%
Cost of removal	3.00%	5.00%	1.00%	2.00%
Other plant-related items	(1.00%)	(3.00%)	(1.00%)	(1.00%)
Renewable energy credits	(4.00%)	(8.00%)	(2.00%)	(3.00%)
Allowance for uncollectible accounts	(2.00%)	(1.00%)
Injuries and damages reserve	0.00%	(2.00%)
Reserve for uncertain tax positions	2.00%	0.00%	1.00%	0.00%
Research and development credits	(3.00%)	0.00%	(1.00%)	0.00%
Other	0.00%	0.00%
Effective tax rate	6.00%	(10.00%)	17.00%	11.00%
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 tax benefit	5.00%	5.00%	5.00%	5.00%
Amortization of excess deferred federal income taxes	(27.00%)	(38.00%)	(12.00%)	(13.00%)
Taxes attributable to non-controlling interest	0.00%	0.00%	0.00%	0.00%
Cost of removal	4.00%	5.00%	2.00%	2.00%
Other plant-related items	(2.00%)	(3.00%)	(1.00%)	(1.00%)
Renewable energy credits	0.00%	0.00%	0.00%	0.00%
Allowance for uncollectible accounts	(3.00%)	(1.00%)
Injuries and damages reserve	1.00%	(2.00%)
Reserve for uncertain tax positions	0.00%	0.00%	0.00%	0.00%
Research and development credits	(4.00%)	0.00%	(1.00%)
Other	(1.00%)	(1.00%)
Effective tax rate	(6.00%)	(14.00%)	14.00%	14.00%