Pension Benefits - Schedule of Assumptions (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CECONY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase (in percent)	3.80%	3.80%	3.80%
Rate of compensation increase (percent)	3.80%	3.80%	3.80%
O&R
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase (in percent)	3.20%	3.20%	3.20%
Rate of compensation increase (percent)	3.20%	3.20%	3.20%
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Discount rate, benefit obligations (percent)	5.15%	5.45%	3.00%
Interest crediting rate for cash balance plan (percent)	4.20%	4.00%	3.50%
Discount rate, net periodic benefit cost (percent)	5.45%	3.00%	2.55%
Interest crediting rate for cash balance plan (percent)	4.00%	3.50%	3.00%
Expected return on plan assets (percent)	6.75%	7.00%	7.00%