Other Postretirement Benefits - Schedule of Actuarial Assumptions (Details) - Other Postretirement Benefits	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Expected Return on Plan Assets	6.80%	6.80%	7.50%
CECONY
Defined Benefit Plan Disclosure [Line Items]
Discount Rate, Benefit Obligations	2.25%	3.10%	4.15%
Discount Rate, Net Periodic Benefit Cost	3.10%	4.15%	3.55%
O&R
Defined Benefit Plan Disclosure [Line Items]
Discount Rate, Benefit Obligations	2.55%	3.35%	4.30%
Discount Rate, Net Periodic Benefit Cost	3.35%	4.30%	3.70%