Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Lessee, Lease, Description [Line Items]
Assets under finance leases	$ 2		$ 2
Finance leases, accumulated amortization	1		5
Right-of-use assets	1	$ 44
CECONY
Lessee, Lease, Description [Line Items]
Assets under finance leases	1		1
Finance leases, accumulated amortization	1		$ 2
CECONY | Subsidiaries
Lessee, Lease, Description [Line Items]
Right-of-use assets	$ 1	$ 1