Related Party Transactions - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		12 Months Ended
	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025	Dec. 31, 2024
Related Party Transaction [Line Items]
Equity, Attributable to Parent		$ 25,596,000,000		$ 24,190,000,000
Other income		143,000,000	$ 201,000,000
Unconditional charitable contribution, accrued amount	$ 12,000,000
CECONY
Related Party Transaction [Line Items]
Equity, Attributable to Parent	$ 21,649,000,000	23,444,000,000	21,649,000,000	22,037,000,000	$ 19,971,000,000
Sale of natural gas		61,000,000	44,000,000
Income taxes due to Con Edison		179,000,000		24,000,000
Funding limit of CECONY to O&R (not to exceed)		$ 250,000,000
CECONY | Related Party, Lending of Funds
Related Party Transaction [Line Items]
Lending period (not more than) (months)		12 months
O&R
Related Party Transaction [Line Items]
Equity, Attributable to Parent		$ 1,449,000,000
Outstanding loans		0		$ 0
CET Electric | NY Transco | Related Party
Related Party Transaction [Line Items]
Other income		$ 0	$ 0