Leases - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Lessee, Lease, Description [Line Items]
Lease, renewal term (in years)	5 years
Assets under finance leases	$ 3	$ 2	$ 2
Finance leases, accumulated amortization	2	2	5
Right-of-use asset obtained in exchange for operating lease liability	3	11
Unrecorded unconditional purchase obligation	262
CECONY
Lessee, Lease, Description [Line Items]
Assets under finance leases	3	1	1
Finance leases, accumulated amortization	2	$ 2	$ 2
Right-of-use asset obtained in exchange for operating lease liability	$ 3
CECONY | Subsidiaries | Lease Expected To Commence In 3 Years With 15 Year Lease Term
Lessee, Lease, Description [Line Items]
Lease not yet commenced, term (in years)	15 years
Operating lease, lease not yet commenced, expected period to commence (in years)	2 years
Minimum
Lessee, Lease, Description [Line Items]
Lease, term (in years)	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease, term (in years)	20 years