Other Postretirement Benefits - Additional Information (Details) - Other Postretirement Benefits - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in liability for other postretirement benefits	$ (70,000,000)	$ (164,000,000)
Noncurrent liabilities	271,000,000	224,000,000	$ 72,000,000
Increase (decrease) in regulatory liabilities	26,000,000
Other comprehensive income (loss), unrecognized net losses	1,000,000
Other comprehensive (income) loss, prior service cost	0
Expected contributions	6,000,000
CECONY
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in liability for other postretirement benefits	(44,000,000)	(138,000,000)
Noncurrent liabilities	180,000,000	$ 154,000,000	$ 27,000,000
Increase (decrease) in regulatory liabilities	16,000,000
Other comprehensive income (loss), unrecognized net losses	1,000,000
Other comprehensive (income) loss, prior service cost	$ 0