Capitalization - Schedule of Carrying Amounts and Fair Values of Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Long-term debt, fair value	$ 25,551	$ 24,651
Unamortized debt expense	249	249
Carrying Amount
Debt Instrument [Line Items]
Long-term debt, fair value	25,801	24,651
Fair Value
Debt Instrument [Line Items]
Long-term debt, fair value	23,633	21,997
CECONY
Debt Instrument [Line Items]
Long-term debt, fair value	24,060	23,409
Unamortized debt discount	240	241
CECONY | Carrying Amount
Debt Instrument [Line Items]
Long-term debt, fair value	24,310	23,409
CECONY | Fair Value
Debt Instrument [Line Items]
Long-term debt, fair value	$ 22,291	20,915
Broken Bow II | Carrying Amount
Debt Instrument [Line Items]
Long-term debt, fair value		$ 59