v3.26.1
Capitalization - Additional Information (Details) - USD ($)
$ in Millions
 1 Months Ended 3 Months Ended
May 31, 2026
Mar. 31, 2026
Jun. 30, 2026
Mar. 31, 2026
Mar. 31, 2025
Debt Instrument [Line Items]          
Common stock through an at-the-market equity offering program $ 2,000   $ 107 $ 776 $ 1,308
ATM program, common stock available for issuance, value     $ 1,800    
ATM program common stock (in shares)     1,018,307    
ATM program common stock cash proceeds     $ 108    
Number of shares of common stock issued (in shares)   7,000,000      
Net proceeds   $ 776      
5.15 Percent Due 2036 | CECONY          
Debt Instrument [Line Items]          
Debt face amount     $ 450    
Interest rate (percent)     5.15%    
5.875 Percent Due 2056 | CECONY          
Debt Instrument [Line Items]          
Debt face amount     $ 850    
Interest rate (percent)     5.875%