Leases - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Lessee, Lease, Description [Line Items]
Unrecorded unconditional purchase obligation	$ 444,000,000
Termination cost	$ 0
Right-of-use assets		$ 8,000,000
CECONY
Lessee, Lease, Description [Line Items]
Right-of-use assets		$ 8,000,000
CECONY | Lease Expected To Commence In 3 Years With 15 Year Lease Term
Lessee, Lease, Description [Line Items]
Operating lease, not yet commenced, term of contract (in years)	15 years