Income Tax - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Income Taxes Disclosure [Line Items]
Income Tax Expense	$ 202,000,000	$ 133,000,000	$ 493,000,000	$ 307,000,000
Accrued income taxes	66,000,000	66,000,000	66,000,000	66,000,000
Deferred tax assets	73,000,000	73,000,000	73,000,000	73,000,000
Estimated liability for uncertain tax positions	12,000,000		12,000,000
Unrecognized tax benefits, increase resulting from current period tax positions			3,000,000
Unrecognized tax benefits, net	11,000,000		11,000,000
Unrecognized tax benefits, interest expenses			0	0
Unrecognized tax benefits penalties			0	0
Subsidiaries | CECONY
Income Taxes Disclosure [Line Items]
Income Tax Expense	187,000,000	119,000,000	462,000,000	301,000,000
Accrued income taxes	89,000,000	89,000,000	89,000,000	89,000,000
Deferred tax assets	64,000,000	$ 64,000,000	64,000,000	$ 64,000,000
Estimated liability for uncertain tax positions	$ 8,000,000		8,000,000
Unrecognized tax benefits, increase resulting from current period tax positions			$ 2,000,000