Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Goodwill		$ 408	$ 408
Goodwill impaired	$ 7
CECONY
Goodwill [Line Items]
Goodwill		245	245
O&R
Goodwill [Line Items]
Goodwill		161	161
CECONY
Goodwill [Line Items]
Goodwill impaired	2
CET Gas
Goodwill [Line Items]
Goodwill impaired	$ 5
O&R Merger
Goodwill [Line Items]
Goodwill		$ 406	$ 406