Leases - Other Related Information (Details)	Sep. 30, 2023	Dec. 31, 2022
Lessee, Lease, Description [Line Items]
Weighted Average Remaining Lease Term, Operating leases (in years)	11 years 7 months 6 days	12 years 3 months 18 days
Weighted Average Remaining Lease Term, Finance leases (in years)	6 years 6 months	7 years 2 months 12 days
Weighted Average Discount Rate, Operating leases (percent)	3.70%	3.70%
Weighted Average Discount Rate, Finance leases (percent)	3.00%	1.90%
Clean Energy Businesses
Lessee, Lease, Description [Line Items]
Weighted Average Remaining Lease Term, Operating leases (in years)		18 years 3 months 18 days
Weighted Average Discount Rate, Operating leases (percent)		4.40%
Broken Bow II
Lessee, Lease, Description [Line Items]
Weighted Average Remaining Lease Term, Operating leases (in years)	11 years 8 months 12 days
Weighted Average Discount Rate, Operating leases (percent)	3.80%
CECONY | Subsidiaries
Lessee, Lease, Description [Line Items]
Weighted Average Remaining Lease Term, Operating leases (in years)	11 years 7 months 6 days	12 years 4 months 24 days
Weighted Average Remaining Lease Term, Finance leases (in years)	2 years 10 months 24 days	2 years 3 months 18 days
Weighted Average Discount Rate, Operating leases (percent)	3.70%	3.70%
Weighted Average Discount Rate, Finance leases (percent)	3.00%	1.00%