Other Postretirement Benefits - Additional Information (Details) - Other Postretirement Benefits - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Decrease in liability for other postretirement benefits	$ 63,000,000	$ 70,000,000
Noncurrent liabilities	324,000,000	271,000,000	$ 224,000,000
Increase (decrease) in regulatory liabilities	9,000,000
Other comprehensive income (loss), unrecognized net losses	2,000,000
Other comprehensive (income) loss, prior service cost	0
Expected contributions	4,000,000
CECONY
Defined Benefit Plan Disclosure [Line Items]
Decrease in liability for other postretirement benefits	32,000,000	44,000,000
Noncurrent liabilities	207,000,000	$ 180,000,000	$ 154,000,000
Increase (decrease) in regulatory liabilities	2,000,000
Other comprehensive income (loss), unrecognized net losses	1,000,000
Other comprehensive (income) loss, prior service cost	$ 0