Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022
Goodwill [Line Items]
Goodwill	$ 439	$ 408
Goodwill impaired	7
CECONY
Goodwill [Line Items]
Goodwill	245	245
Goodwill impaired	2
O&R
Goodwill [Line Items]
Goodwill	161	161
CET Gas
Goodwill [Line Items]
Goodwill impaired	5
O&R Merger
Goodwill [Line Items]
Goodwill	406	406
Gas Storage Company | CET Gas
Goodwill [Line Items]
Goodwill	8	1
Residential Solar Company | Clean Energy Businesses
Goodwill [Line Items]
Goodwill	14	14
Battery Storage Company | Clean Energy Businesses
Goodwill [Line Items]
Goodwill	$ 18	$ 18