Income Tax - Schedule of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Unrecognized Tax Benefits [Roll Forward]
Balance at beginning of period	$ 9	$ 11	$ 23
Additions based on tax positions related to the current year	2	4	8
Additions based on tax positions of prior years			3
Reductions for tax positions of prior years	(2)	(6)	(11)
Settlements	0	0	(12)
Balance at end of period	9	9	11
CECONY
Unrecognized Tax Benefits [Roll Forward]
Balance at beginning of period	5	7	8
Additions based on tax positions related to the current year	2	4	4
Additions based on tax positions of prior years	0	0	1
Reductions for tax positions of prior years	(2)	(6)	(6)
Settlements	0	0	0
Balance at end of period	$ 5	$ 5	$ 7